Charge double when they advised they won't

Anyone who has a medical aid NEVER go to Doctor T Viljoen in Honeydew Ridge, I was a first time patient and went to see him on 16 May, the receptionist told me for follow ups less than 5 workong days he won't charge me again, I went back for follow up on 20 May and they charged me again, now I am struggling for almost 4 weeks to get my refund and the Receptionist keep on using the same excuse they extremely busy, but they could not wait to take my money, never will I go back and I want to warn other patients