Payment Reversal Issue

I mistakenly paid a wrong account and phoned FNB to reverse it, I was asked to fill a form which I did and sent it back shortly after it was sent to me. I have been following up via mail and phone calls but to this date I haven't received any response nor feedback. The frustrating part is that the call centre isn't helping either, I have been sent from dep to dep until I run out of freaken airtime. I am super annoyed and dissapointed with the whole service. From the 14th May 2022 it is now the 9th of June 2022 still no response?? How pathetic!!!!!