I have just found out that since I was promoted in March 2018, I have been overpaid. I am part time, working 24hrs, and have been paid for 27hrs. My company are sending me a letter regarding repayments. I'm bricking it that they will want a big lump of cash in one go. I don't have any savings. Has anyone got any experience of this? I don't think it will make any difference, but for the record this is their mistake as they put my hours wrong on an internal system. My mistake was not checking my payslip now thoroughly. My only defence is that I didn't have an easy comparison as I was on maternity leave and came back to the promotion. I'm an idiot still.