Been charge for data that i did not signed up for0

I have taken a contract on 24/08/2015 for *** for a IPad. This does not have a dialpad. From the beginning the account was R399.00 but suddenly it was from Oct 2015 R additional R500 was charged which I did not subscribe to. I have sent a email the lady did not come back to me. In December I received another account for November which the billing was done again for the additional R500. I have phone in on the 14th of December and spoke to the person in question which gave me the promise that it was removed and blocked when data is finish I can buy data. I sent him a follow up email to ensure that this had been done. I went to a Telkom store on Friday 8/01/2016 to check my account. Great was my surprise to see I have been billed again for the R500 additional data. The person in store checked and told me that the limit is zero and he don't understand why I was billed. I was put thru to a call centre who was also unable to assist in this regard.I am taking my complain to the consumer protection as I am not going to be ****** by Telkom from my hard earn money every month.