In the doldrum days just before New Year, the ghost of Christmas Just Past haunts the shops like a particularly tatty revenant from the pages of Dickens.

If the eminent Victorian had written his most famous festive story today, I’ve no doubt that the chains Jacob Marley forged in life would be formed from credit cards and The Ghost of Christmas Present would be wrapped in sales banners and loaded down with plastic bags full of pointless tat.

I braved the post-Christmas sales a couple of times in the last week or so, but it was a depressing experience. The twinkling lights and tinsel garlands that looked so jaunty and promising right up to closing time on December 25 now served as a limp reminder that the annual escape from rational reality was well and truly over.

Christina Rossetti was thinking mainly about the weather when she wrote her own seasonal classic, but, truly, there is nothing bleaker than a price-slashed high street full of iron-hard, stone-faced shoppers to chill the soul.

How soon the season of good will to all men is forgotten. When did people become so rude?

Last week I lost count of the number of times I was practically mown down by women wielding baby buggies bigger than chieftain tanks, forced into the gutter by groups of youths who couldn’t be bothered to make space on the pavement as I tried to pass them, or knocked to one side by people who were so intent on talking into their mobile phones that they didn’t see me.

Not once did anyone offer an apology or even a murmured sorry as they poked, bumped, crushed and pushed past me. The worst offender was a young woman who whirled around at the entrance to a shop to shake the rain off her sodden umbrella. Not only did she drench me, but she hit my nose and nearly poked one of my eyes out too - without actually noticing that I was there.

Later on, during that same abortive shopping expedition, I was standing in front of a rack of shoes idly wondering if I could smuggle another pair of cute fur-lined boots into the house without rousing the suspicions of my husband (who although currently recumbent on the sofa watching TV was easily as alert as a sniffer dog at Heathrow when it came to new shoes).

I was just about to lean forward to examine a particularly alluring pair more closely when two apparently glamorous women barged in front of me and blocked my entire view of the rack. The fact that they physically had to force their way past me to take up this prime position didn’t prompt either of them to register my existence.

I consoled myself with the fact that the bargee on the left had so many blonde hair extensions attached to the back of her head that bald patches were beginning to show through her matted mane.

And it wasn’t just customers who were badly behaved. Writing as someone whose sister-in-law works in retail, I have every sympathy for beleaguered shop staff at this time of year. Every year her festive break appears to consist of a few snatched hours on Christmas Day between an evening marking up the sale items after closing time on December 24 and opening the doors to the stampeding horde at 8.30am on Boxing Day.

Far from being a restful time, for her Christmas is two-month-long feast of stress, interminable opening hours and aching feet, garnished with rude customers and potentially violent shoplifters.

I’m not joking when I say that the first sound of Wham’s Last Christmas - piped throughout the shop at the beginning of November - makes her want to hide in the stockroom and muffle her screams in a pile of sequined velvet.

So, it’s true to say that I really do understand how difficult and frustrating it can be at this time of year if you are working in a shop and are faced with the seething mass of humanity at its venal, voucher-laden, turkey-stuffed, blank-eyed worst.

However, it is not acceptable to be rude and lazy.

Given that these are desperate days for the high street, you’d imagine that shops would be giving their staff regular pep talks about ‘going the extra mile’, wouldn’t you? Apparently not.

One afternoon last week, I wanted to try on two pairs of jeans and took them to the changing room. Although it was only 4.45pm, the entrance was blocked by a rack of clothes. Beyond the rack a tutting middle-aged assistant was busily arranging a second rack of items that customers had tried and rejected.

‘Excuse me,’ I called across the fabric wall. ‘Are you closed?’ The woman didn’t look up, but she grunted something that sounded like a yes and crouched a bit lower so that I couldn’t see her.

‘I just wanted to try these on. Is there another changing room?’ I asked, politely.

‘We’re closed - you can buy both pairs and bring one back.’ came the disembodied voice.

This wasn’t ideal - not when you‘re as short as me. I definitely needed to try them on. In a spirit of shop-floor solidarity, I wondered if the store was closing early, perhaps at 5pm, because of the Christmas schedules? Perhaps that was why she wouldn’t let me in?

‘What time do you close today?’ I asked in what I thought was a friendly, sympathetic way.

No answer.

‘Er..hello…’ I tried again. ‘Is the shop about to close?’ At this point the woman erupted from behind the rack, deliberately turned her back on me and almost ran to the other end of the changing room where she disappeared behind a slammed door.

I would have been tempted to name and shame this shop, had it not been for the fact that the other assistants there were so helpful and friendly.

I decided to take the risk and buy one pair of jeans. At the busy till, staffed by three young girls, I asked what time the store would be closing that day and was amazed to find that it was due to be open until 6.30pm - still a full hour and half away.

When I asked why the changing rooms had closed so early, the assistant on my till looked surprised and horrified. “It definitely shouldn’t be. X should be there, shouldn‘t she?.”

The girl addressed this question to a colleague who pulled a face that eloquently expressed everything I felt about X.

The friendly girl on my till then looked at the queue of disgruntled shoppers behind me and asked if anyone else wanted to try things on. Lots of us did - so she apologised, led us back over to the barred, deserted changing room and opened it for again us - clocking up about £800 worth of sales in the next 15 minutes or so - which I am sure would warm the tiny cockles of Sir Philip Green’s heart.

I’m not usually one for New Year resolutions, but here’s a plea to everyone - let’s make 2012 the year of being polite.