Refusing to refund mistakenly deducted amount

Thrifty deducted an amount for rental and for an extra driver after I already paid with a third party called rentalcars.com. They immediately informed me that it was a mistake on their end and that they will refund my card. It has been almost a month now being shifted from pillar to post with no refund as yet. I went to the Airport branch and spoke to a sales manager called Rowan who ensured that he would process the payment immediately. He blatantly **** to me by even sending screenshots of the proposed refund. More than a week has passed since this supposed transaction and I have not been refunded. This is an ********* business and should not be supported. Customer service is the worst I have ever encountered.