I left my job in July 2019 and believed I was overpaid in my final payslip. I raised it and was told that this was a common occurrence and that they would write to me within months to request it back.
In September 2019, they then paid around £1000 into my bank account, which concerned me as I had received a random payslip from them for a different amount (around £900). I worried they had not taken me off the books and contacted my manager immediately to flag this, asking for my email to be sent to the department that deals with these issues so that they could check as I did not want money in my account that didn't belong to me.
My manager did not pass the email on, instead reassured me that this money was owed to me and they had made this calculation based on holiday days I had not taken. She assured me the balance should be square now and that a final payslip and P45 would follow. I did receive these months later, although the totals didn't make much sense to me. As more time passed and no further contact was made I spent the additional money.
Yesterday, out of the blue, I had a letter from them saying they had made a mistake and demanded £800 be paid into their bank account within 14 days. I am going through consultation for my current role, and even if I secure something will be starting maternity imminently, so my financial situation is dubious. This feels really unfair and I cannot believe they are allowed to do this.
I know the law says that they can come after you for money within 6 years, but I would assume that is to protect them if they had overpaid me and I hadn't said something. I tried to highlight the issue with them immediately and contacted them twice about my concern and they took no action but to assure me it was mine. Why is it my problem that they made a mistake and I now have to pay at a really difficult time in my life.
I have emailed them to make these points and they have offered me a payment plan. I doubt I can do the £1 a week thing that people joke about, but I don't want to give it to them. I just want them to write it off if they hadn't noticed all this time! They are a multi-million dollar global company.
I know about the law of estoppel but I was under the impression it's impossible to prove. Does anyone have any experience of this or advice?