Release my money into my cheque account

It is almost 2 months that I have been waiting for FNB to release my funds into my Gold Cheque account. In June I rented a car from Avis and used my Gold Cheque account card for the deposit hold. Avis has released all holds on my account. All balances on my bank statements do not match the balances on my SMS notifications. On my bank statement it shows that I have over R2000 available however, a fee of R8.50 for "Debit Card POS Unsuccessful" has been deducted from my account numerous times. I have emailed FNB and eventually when I called FNB, I spoke to Mpho Kubheka who advised me that all I need to do is to complete a "Cheque and Debit Card Dispute form" and send it back to FNB. I completed the form and sent it on the 27th of July. I received an automated response from FNB confirming that they have received my email and that they will respond within 5 business days. I only received feedback regarding my dispute yesterday, 6 August 2018. Not only did I receive feedback after 11 days, but I was also informed that they are unable to process my dispute and that I need to resubmit together with the required communication with the Merchant/Service Provider (Ref No ********** 7_ ********** 34). I am not sure what "communication" I need to send from Avis to FNB, to have my funds released back into my account, when they are able to see that they have not released the funds owed to me as Mpho explained. Another amount of R110 has also been deducted from my account for "Item paid no funds" but on my statement it shows that I have available funds. The total amount owed to me is over R3000. I am really disappointed in FNB as so many people convinced me to switch to FNB. Not only are the bank fees ridiculous but then I also have to go through so much trouble and effort just to get my own money from them. I am going to switch back to my previous bank today.