Credit card hold not refunded after almost a month - disgusted

I am truly disappointed with First Car Rental. It has been almost a month and I still did not receive the hold amount for the deposit back from them. I have made repeated attempts to chase this up and after each reply on their system they close the case as if it has been resolved. I have to repeatedly reopen it as I still do not have my money back. The last 4 mails they did not even bother to reply to. They simply dont care and frankly the service stinks as if it was me I would have made every effort to try and resolve this for my client. Truly sad!!!!