In April I accidentally withdrew money from my Nationwide account with my M&S credit card instead of my debit card immediately incurring a charge. My monthly direct debit had only left my Nationwide account that day so I decided to pay off the balance on my M&S credit card account, that day, to avoid further interest charges. I accessed the M&S bank online possibly through the app, otherwise via Google and found a sort code and account number for my credit card account. I did a bank transfer for a substantial sum and the Nationwide security check confirmed that I was transferring the money to the M&S bank. The money did not show on my credit card account that day but the monthly direct debit takes a day to show. As it did not show the following day I contacted M&S and a helpful lady said she would look into it and in the meantime gave me a temporary credit for the amount transferred. When I checked to see if the transfer had been found I was told that it had gone to an HSBC account but HSBC would not investigate it as the transfer was not from M&S Bank. I was given, in error, another temporary credit which was later removed and I was also given two compensation credits as the person who had handled my first enquiry had not followed the proper procedure. I contacted Nationwide and asked for a trace to be put on the payment. I heard nothing so I contacted them again and was told a trace had been put on the payment and I would be notified when it was answered. I next heard from M&S bank that the transfer had not been traced and the temporary credit would be removed. Then they told me, sorry it had already been removed (it hadn’t) then they told me they had removed it. They changed the dates on the account for the temporary credits to the day of the original transfer, I do not know why. I contacted Nationwide who told me they had received an email from M&S bank a month earlier stating that the money had been received and credited to my account giving my name with first and surnames reversed. (The bank transfer had had as a reference my M&S credit card number) I have given M&S all these details but they seem to have closed their enquiry. No third party was involved so this is not an ordinary scam. Is it just total incompetence or is an insider at work intercepting bank transfers? Has anyone else had similar problems? As far as Nationwide is concerned they have been told by M&S bank the payment went through and had already been credited to my account which is why they did not notify me of the result of the trace. As far as M&S bank are concerned they have not received it so I must pay again. I have been amazed at the dilatory response to a probable internal scam. I am taking this matter to the Financial Ombudsman. At age 89, with impaired hearing , this has caused me considerable hassle and stress. I wish that I had consulted this website before taking out the M&S credit card.