Fed up with cellc always giving such terrible service

I have been having the same on going issue with cellc. All i want is for them to refund me the R1350 that they have debited out of my account. Its more than 3 days and they have not done anything to rectify it as my medical aid is currently suspended due to cellc debiting me. I can hardly get old of anyone to rectify this...no customer service what so ever .....this will be the last from me with cellc