Struggle to cancel my Telkom Mobile Contract

I have a 10GB Data Only contract with Telkom Mobile (8ta). I went to the Telkom Mobile store on 19.01.2016 to put in a cancellation request. The employee told me it would take 30 Days for the contract to be cancelled and as you pay in arrears I would pay my last premium at the end of February 2016. My premium went off at the end of February 2016 but on March 01st they loaded me with another 10GB of Data. Since the 19.01.2016 I phoned almost every week to check on the status of the cancellation and every time I get the same answer...a consultant will contact you regarding the cancellation. It's been past the required 30 days now and still nothing. I could have upgraded the contract 3 years ago but did not want to thus I was only on a month to month basis. I am not going to pay for the 10GB data you sent me for March 2016. I want this contract cancelled NOW! Next I am laying a complaint with the Consumer Rights Organisation. My case number is ***6.