FNB unable to provide proof of payment

I have been trying to get prove of payment from FNB for the past month without any luck…they are sending me from pillar to post.

What happened was I hired a car on the 23rd of November through Avis which I swiped R4500 (holding deposit) at King Shaka airport, on the 1st of December R1774.35 was then deducted from my account for the rental. Avis then advised that they have instructed FNB to release the funds (R4500) back into my account on the 1st of December but that money is not reflected on my account, they then advices that it was released but it will not reflect on my account but instead it will just increase me balance. I then downloaded a statement to see if my balance had increased by the amount in question but there’s was no increase between 1st and 2nd of December. When I ask the to show me the increase they can’t and keep my on the line for more than an hour but still the matter is unresolved, this has been going on for a month and a half and till today FNB cannot prove to me that the money was indeed released back into my account.