Bad Service

I renewed my celphone contract with MTN at the MTN store at Langeberg Mall outlet in Voorbaai, Mosselbay. The person helping me did not cancel my previous bizz activation that cost me R60.00 per month extra, the person did not inform me that by not putting a data credit limit on my phone that I am going to get a huge bill. Although I am useing wi-fi at work and at home, I still get these huge bills and could not understand why because I don't even put my mobile data on at my phone's settings! Since February 2014. I went to MTN Oudtshoorn to sort out the bills, and no one could help me, they just said that I am late on payments and that I need to pay my bill, after I made all the payments up to date! I contact Joline at Mosselbay Mall Heiderand today 03/06/15, and thanks to her the problem have been solved! But I still have payed all that Money to MTN for more than a year and not even useing their service!!!<br> Hello Peter can U please help me!