Refund taking for ever

As for the life of me I can not understand why it is so difficult to repay funds back that was paid to much into an account. As from 1 Nov 2022 I have been struggling to get a credit back from you. The Finance department can not receive calls and the emails are always the same, allow us uptoo 48h to respond. On 21/11/2022 I received a mail the funds was transferred... No it was not! Again and again I must send bank statements to proof that the finance department is lying. Please sort this out and refund the credit.