After 13 years of running this helpline and writing this column I have what you might call an extremely ‘healthy’ scam file – it takes two hands to lift it.

In all those years, only two calls have seen me ringing retailers back after investigation to say, yes, it is legit, and it has led me to give the standard advice: never say yes to a cold call.

The first good one was maybe 10 years ago but now here is the second one. Fresh off the press, as it were.

Clare Welsh rang to say that a guy had dropped into her shop, Craigton Post Office, to ask if she cared to support her local coppers with an ad in a Police Federation diary. She trades directly next door to a huge police station that services the whole of Glasgow South so was amenable to this idea.

“He was very chatty and friendly,” says Clare, “and I signed an agreement for a quarter page ad for £170 plus VAT.”

Clare says she felt good about it at the time but then, in bed that night, tossing and turning in the heat of that week, she had second thoughts. Why did she not get any sort of copy of the agreement she signed which, she also remembered, had mentioned no chance to cancel once signed?

All she could remember was the mention of a company name. Lancaster?

I had to admit when Clare called that I was not confident of a good outcome. However, I phoned the Scottish Police Federation in Glasgow and Lesley Stevenson in the press office confirmed that Lancaster Partners sells space in the Feds’ diaries. Lesley went to the trouble to check which areas had been canvassed on the day Clare mentioned and it all tallied.

Isn’t it a shame that so many ‘real’ scamsters spoil it for the genuine article? And by the way, the advice still stands: never say yes to a cold call. And deals always hold.