Missing payment

Missing payment- I made a deposit of R10 000 into my Discovery Credit card account on the 3rd of April 2020. On the 4th I received a SMS informing me that Discovery bank are moving all accounts over to Discovery bank from FNB. This meaning my Discovery credit card account are now been moved from FNB to Discovery Bank. Since they moved over, the deposit of R10 000 I made on the 3rd of April 2020, does not reflect on my Discovery credit card account. I contacted Discovery on the 6th of April 2020 to found out why is the R10 000 not reflecting on my account. I also mailed them proof of payment. It’s been 5 and a half weeks and still Discovery bank could not solve the problem and the money is still missing. I phone them almost daily and I am getting the same reply over and over again and that is that they are still investigating and waiting for FNB to give them clarification. I even spoke to one of their managers, Hope Munro who is also not able to solve it. I am very disappointed in Discovery bank and I hold them accountable