POOR SERVICE

I have a data contract with Cell C which I have decided to cancel.This contract has a 3 sim cards sharing same data. I went to Cell C store to cancel it and they told me to call the customer care as they are the one who cancel the contracts.I then I phoned them and they transfered me to retention department. The retention department advised me that I would have to pay the commitment amount to cancel it, of which I have paid into the account they gave and I sent them the proof of payment. Surprisingly the contract was not cancelled instead they deactivated the main sim card and leave others active so that they can load the data on and charge me. After realising that I was billed for the data that I thought I have cancelled its contract I went again to cell C. I found myself wasting my time by going there because I have been sent from pillar to post by customer care and retention department. Please I want this contract be cancelled. I don'twant it anymore.