BAD ATTITUDE / BILLING / UNWILLING TO ASSIST

On the 12/01/2015 , I got a message on*** Unusually high Usage has been detected on your cellular nr exceeding R3810.97 , I Immediately contacted *** and every time the phone will ring and it will be disconnected and then I tried from the land line , O boy was that a mission, No answer,... Then at 11H00 on the 12/01/15 I switched off the phone completely Until the 13/01/15 at 16H50 when I phoned from the cell phone. I first spoke to a lady with the name Thandeka, She then informed me this is an open account and that my billing is standing on R5800, what R2000 extra since the 12 , How is that possible I have not been using the phone, I begged her to help me etc but yet I was transferred to Customer Services , What a mistake, I spoke to a Lady , cant recall her name, But was she rude, she then told me the account is not closed and billing will run and they will Deduct R2646.58 from the account , The more I am trying to sort this out the less hey listen, I mean I only use Facebook and Whatsup what can possible eat R5800? and yet I now I have to wait 1-7 working days for them to contact me back, I mean they will deduct but they don't want to help me? What kind of service