Still have not received my deposit back

I have not received my deposit back. We rented a car for 1 day and gave them 21 business days to return my deposit as to date i have not received anything. Called multiple times been told that my bank hasnt released the fund as it has been put on hold. Called the bank and the bank said no amount has even been deposited in the account. This went on for 2 weeks, calls between headquarters and the bank , as thrifty said they paid it but its the bank not releasing the amount. Now the new story is they never received my deposit in the first place, so they didnt even refund the deposit. Even tho when we paid with the credit card it was accepted????? I am very confused on the 2 conflicting stories. Now we submitted the proof that the amount has gone off my account and i filled in another form to get my deposit and still no deposit or any responce.