Unauthorised debit

I had an unauthorised debit coming off my account from Cell C, I promptly called their call centre to let them know about this and I was assured that the money would be credited back to me call case: ***. I was told that this will be done in 7 working days, those days went by but still the money wasn't paid back to me. I called them again and now I was told that it wasn't 7 but 14 working days instead, again I waited and nothing after those 14 days. I called again and this time I was told that the money had been credited into my Cell C account instead of my bank account and I was told that I'd get it in my account within 7 working days and again I was issued a call case number: ***. I waited 7 days and still the money hasn't been paid back to me. I called them again today and again told something else and that they'll try and log a case to have it resolved, I mean how many times should I call them to have my problem fixed. Is this Cell C's strategy to get people to give up and don't they have SLA's.