Hold still on account after returning car and Invoice being paid

Hold was put on account for a monthly Rental Amount of R6900.00 on 10 March 2021. After Returning the vehicle I received the invoice on the 22nd of April 2021 and the amount for the invoice was deducted on the 26th of April 2021 thereby paying my account with Avis in full. Transaction concluded yet there is still a hold on my account for R6900.00 pending debit? This is the funds that were suppose to be used to pay the invoice, not keep it on hold indefinitely and deduct an additional R6500 and change to pay the actual invoice?! Remove hold from the funds in my account immediately as I have paid what I owed and the pending transaction since 10 March is my money that is needed elsewhere. This is **********. I would not recommend Avis as apparently they cannot manage their banking. I understand the final amount was different from the initial amount put on hold. But you release the hold and deduct your final amount from that, not take money in a transaction that was not authorized. Avis, you owe me R6900.00 from the pending transaction on my account. You cannot deduct funds and still keep a hold on the initial amount as well!