Avis *****ing money and not willing to pay it back.

Since November last year, I've made a booking for a Polo Tsi, at Margate Airport. Booked via the app, got kicked out. Booked online. I then went to Avis at Margate Airport, no car. Asked them to call me if it's there. No call back. Result. 2 payments of R583 went off from my account for cancelation fee or something. Manage to get the 1 refunded. Struggling since for the 2nd payment to be refunded. Went to the Avis at Margate Airport last week Monday. Mailed the employee there my bank statements as proof directly from my bank app in front of him. Was informed a refund is requested and was approved. Will take 4 to 7 days. Still no payment received. Head Office is a joke. I'm so disappointed in Avis. Quick to take your money. Take forever to get a refund back.