Why did all 12 cheques I deposited at the Post Office disappear? TONY HETHERINGTON investigates

Tony Hetherington is Financial Mail on Sunday's ace investigator, fighting readers corners, revealing the truth that lies behind closed doors and winning victories for those who have been left out-of-pocket. Find out how to contact him below.

M.H. writes: I am a director of a small agricultural supply business, contacting you in desperation. My firm deposited 12 cheques for Barclays bank – totalling £6,212 – at the local Post Office. They were never credited to our account. I have spoken to the bank every week for the past month and had no support.

Tony Hetherington replies: The Barclays branch in your town closed its doors three years ago. Account holders were told to use branches in two nearby towns. Alternatively, Barclays advised: 'Cheques can be deposited at the Post Office. Please allow an extra two days for cheques deposited using a pre-printed paying-in slip to reach your Barclays accounts.'

I asked the bank what had gone wrong, and staff told me: 'We're really sorry that a number of cheques paid in by Mr H's company were lost in transit by Royal Mail.'

It offered you £200 after acknowledging that you would have to contact the dozen people and firms whose cheques were lost and ask them for replacements.

However, a bad situation became worse. You deposited a further 11 cheques at the same Post Office, with a total value of £6,593, and they also failed to reach your Barclays account. I began making inquiries again, and a day later ten of the cheques turned up, leaving just £27 missing.

Barclays raised its offer to you to £300, and the bank will also meet any expenses faced by your customers who have to ask their own banks to cancel the missing cheques. I do hope procedures at that Post Office branch are tightened up as well.

Ms T.J. writes: Vinted and Mangopay are refusing to release £27 – the proceeds from items I have sold using their services.

I have been asked to complete a Politically Exposed Person questionnaire, which I already did months ago. I am now being asked to supply photographic evidence such as a copy of my passport or driving licence.

I refuse to do this, as I don't know why they need such personal information. It seems they are thinking of any way not to release my money.

Tony Hetherington replies: For those who do not know it, Vinted is an online business based in Lithuania which acts as a middleman for anyone wanting to sell or buy secondhand clothes and similar items. And Mangopay is a money transfer company based in Luxembourg.

I contacted both companies but Mangopay, which is allowed by the Financial Conduct Authority to operate in the UK, failed to offer any comment or explanation at all.

Vinted, though, replied quoting a 2004 Luxembourg law dealing with money laundering and terrorist financing! It referred to this as a 'Know Your Customer' procedure that Mangopay must apply.

But hang on a moment – surely Mangopay's customer is Vinted, not you? Well, apparently you are really a Mangopay customer. Before putting anything up for sale on Vinted, it seems you should have studied the Lithuanian company's 20 pages of terms and conditions. These reveal that it uses four money transmission firms, all based in different countries. And when you use Vinted, you are automatically enlisted as a customer of one of these firms.

This, in turn, means you have to abide by Mangopay's own 21 pages of terms and conditions, which give it every right to cling on to your £27 until you jump through a series of hoops. One of these hoops is that if Mangopay suspects you are a crook, an arms dealer, an international diplomat or a high-flying politician, it can investigate you as a potentially corrupt Politically Exposed Person, rather like a Russian oligarch whose assets might be frozen.

The pages of questions issued by Mangopay include asking you whether in the past 12 months you have been a head of state, a supreme court judge, or a general in charge of an army. And even if you answer no to every question, Mangopay warns that simply by returning its questionnaire you are accepting that it can demand further information and documents from you.

So, are you as corrupt as a villain from a James Bond movie? And just what did you sell on Vinted to spark Mangopay's suspicions?

You told me: 'I'm retired and trying to downsize, selling a few things.' You sold a pair of men's loafers for £8, a dress for £4 and a vintage-style trench coat for £15. As for being a Mangopay customer, you protested: 'I never signed up to be one. If I had been given that option, I would never have signed up to Vinted in the first place.'

The Trustpilot review site is full of protests from people in your position. And, just a few weeks ago, my Mail colleague Sarah Vine publicly ditched Vinted after struggling unsuccessfully to get money owed to her. She wrote: 'Well done, Vinted: you've wasted several hours of my few remaining years – and swindled me out of £62.50.'

Surprisingly, the online barrier to your account suddenly vanished after I started questioning it. You grabbed your £27 while you could. But it was 'a really quite appalling way to operate a business', you told me. I can hardly disagree.

If you believe you are the victim of financial wrongdoing, write to Tony Hetherington at Financial Mail, 9 Derry Street, London W8 5HY or email [email protected]. Because of the high volume of enquiries, personal replies cannot be given. Please send only copies of original documents, which we regret cannot be returned.