I was overpaid in a previous job. Once it was pointed out I agreed a repayment plan for repayment to be taken from pay. I met most of these before leaving the company. I am.now being asked to pay the remainder of the gross outstanding. I haven't had the gross amount and there isn't a payroll system in place to offset the tax, so should I be paying? It doesn't seem.right that I have received net but paying back gross.