Messed up reversal of cheque card transaction process

I made an online payment of R5434.00 on the UNISA website on the 21st Dec 2019 which never cleared,just sat as pending in my account for weeks. I requested the bank to reverse the online payment on the 6th Jan 2020, which was reversed on the 13th/14th Jan 2020. On the 17th Jan 2020 R5434 was again deducted from my account by UNISA/FNB which I know nothing about. On 19th I requested FNB to reverse my money because I had paid UNISA at their offices on the 7th Jan 2020. Till today i haven't received any feedback from FNB, when I call they tell my request is still being processed and 9 days have passed already. I just want my money because UNISA doesn't even have a trace of it or received it so they can't assist me.Where did my money go? I'm really getting tired of FNB and their "DONT CARE ATTITUDE""