Poor service & ripoff

Rented a car at Cape Town Int’l and returned it same day (20/08). Still haven’t been credited back. Their excuse, after I contacted them: “we sent an e-mail to update your banking details”, which was to old e-mail address even though their agent at airport had “updated” my details and took my mobile number. Didn’t bother to Call me when no response on e-mail. Mind you they had my banking details on the form from their agent at airport. Why bother filling in that if they not gonna use it! Still haven’t been credited even though I queried this last week Friday!