Fraud on Halifax PPI payment. Need advice on how to escalate


Hi all. I recently received a letter from the Halifax regarding a PPI settlement and in the letter it advised me the payment had been made to an account I did not recognize. When I called the Halifax PPI customer services line they advised me that they had spoken to me on the 28th of July at which point I provided them with the account details. I have never spoken to anyone from the Halifax regarding this claim or provided any account details.
I am worried that someone within the Halifax has created a fake entry in their call logs to say they spoke to me and I provided them with account details presumably to appropriate these funds to an account they control. I managed to get the sort code and account number from PPI customer service and the account is with Monzo bank which apparently is fairly well know for being used by scammers.
My problem is that I can't get to speak to anyone within the Halifax that will help beyond the PPI customer services number and I don't have much faith they are escalating this. I have called them quite a few times, over several days and there seems to be no record of my previous calls.
So anyone any idea's where I could go from here? It seems odd that the Halifax look like they have someone fraudulently appropriating funds working for them and I can't get to speak to anyone within the Halifax that will take this seriously. If they have done this to one customer it seems unlikely they would stop there. I have called every number I can find for the Halifax and keep getting told they can't help and end up getting transferred back to the PPI customer service line which have been no help at all.
Replies
Send a formal written complaint and let them sort it out.
OK so someone who knows you well enough to pass security with the halifax has stolen your payout? Look close to home and find the culprit. It is not going to be the halifax.
I don't think anyone has compromised my security details. The service desk log says they called me and I provided account details. That to me is why this looks like an inside job as I never spoke to anyone to provide them with account details on any phone call. So the service desks logs say they called someone at which stage the account details were provided. They only have my mobile number and no-one else would have answered that call on my mobile. The PPI handling centre also appears to be outsourced so I don't think this is a matter of someone with the Halifax being involved.
I never provided any account details as part of the PPI claim. Previous PPI payments I received were always in the form of a cheque.