No real help from vodacom

Is vodacom ripping people off Sighned a contract with vodacom for a tablet. When arrived. Did not like. Returned it within given period. Did not realize they did not cancel contract. Was charged a year for contract. About a quarter has been refunded and for last eighteen months been fighting to find out how refund was calculated. Also charges were made to my account for things like hotspoter etc. Never sighned on. Was cancelled but no refund. In The last couple of months now being charged for entertainment. Also never subscribed. Refund? I have requested to see someone Accounts,cancellations and customer care cannot help