I was in Marks & Spencer in Workington when a message started to come over the loudspeakers. ‘Achtung, Achtung,’ or so it sounded. The West Cumbrian accent can sound a bit foreign. I didn't quite take it in. I wasn't buying anything in M&S — dear God, do you think I'm made of money? Anyway, I've got loads of clothes, why would I want any more?

I was using M&S as a short cut. I’m not sure how well you know downtown Workington, but you can walk straight through their M&S from the car park and reach the cheapo shops behind, without going round the block.

The special deal turned out to involve Oxfam. Now you’re talking, I thought, that’s a shop I do use. I stopped and listened and it seemed to say that if you took any of your old M&S clothes to Oxfam, you’d get a £5 voucher to spend at M&S.

Though I don’t shop at M&S, and don’t need new clothes, I was instantly interested. A bargain is a bargain — but it was a bit confusing. How many old clothes did you have to take? Could you buy anything you liked with your free £5 voucher, such as a household necessity like Beaujolais?

It so happens that there’s no Oxfam in Workington, and I’ve looked everywhere, which made it seem a bit strange. Perhaps it was just a bit of M&S PR, to make it look kind and caring. It could all be a nonsense, like so many special offers are.

I remember when our older daughter, Caitlin, returned from 12 years in Botswana. I came down one morning to find her on the phone, hanging on.

A voucher had dropped out of some newspaper which had instructed her to rub it to reveal numbers and find out if she’d won a prize. Which she had! She was dead excited, poor lass, not being used to the wicked ways of the West. I grabbed the phone straight out of her hand, shouting at her for wasting my money on a stupid premium- rate phone line.

I expected this M&S caper to have similar drawbacks, but all the same, when I got back to Loweswater I asked my wife if she had any clothes she was thinking of giving to a charity shop — she often does, being kind and caring. I’ll hand them in for you, pet, I said, next time I go to Cockermouth. There’s a good Oxfam there, with an excellent book department.

Two of her bits turned out to be M&S and I found that one of my old country jumpers had also been bought there — a Christmas present from one of the family, years ago. I wasn't planning to give it away, as I never do. Instead, I use it for gardening and then, when it really falls to pieces, boil it up with some nettles and field mushrooms and make a paté.

I took my three M&S items to the Oxfam shop in Cockermouth and said that it wasn’t clear from the announcement whether you would get one £5 voucher per item or one voucher per visit.

The salesperson put her finger to her lips in a “Shush” sign and from the till took three vouchers and gave them to me. I handed over my swag and made a dash, just in case there had been a mistake and I should have been given only £5 worth of vouchers not £15.

I was well pleased, having got all that money for nothing. Until I got home and read the small print on the vouchers. It was true you got £5 off — but only if you spent £35 or more per transaction and it had to be on clothing, home or beauty products — of no use to me. I would never spend more than £10 on clothing, and I’m well beautiful enough. Secondly, you had to spend these vouchers before September 30.

I don’t plan to go to Workington again for some time, architectural and cultural wonder though it is, and there’s no M&S in Cockermouth.

So this is what I’ll do. I’m not giving away £5, sir. I’m not giving away £10, madam. I’M GIVING AWAY THE WHOLE £15!

The first person who writes to me (c/o The Sunday Times Money section), with a stamped addressed envelope, please, will get all three vouchers. Can’t say fairer than that.

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