Dont take anything from mondo or telkom

Worst company ever I took a contract phone wit dem in january I received the phone apon receiving the phone I could not hear on the phone , I phoned dem an they came too collect the phone to replace it , after 4months of dem having the phone an still debiting my account no1 has contacted me , so I called them too cancel the contract an still my account is been debited of large amounts 9months later , what do we do in situations like this , ive had it with mondo an telkom