Return my refund..... Worst experience ever

If there was a zero star that's what you deserve when it comes to client service. What an exhausting and frustrating experience in these trying times. I have sent emails regarding my refund on a loan that was overpaid, i sent proof and response was, it will be sent to the relevant department and that department hasn't contacted me i am the one following up but at no avail, When I called the contact centre the consultant was not helpful at all, she couldn't see any query was logged and requested to do it but up to this day nothing has been processed, i can see the payment on the LOAN HISTORY, im not sure if any of you can't see it, wasn't your system supposed to pick it up and return to the client like how other reputable financial institutions do?. May you kindly process my refund and give what"s due to me.