failure to cancel contract

My name is Freddy.I had a contract with telkom mobile. 2 years ago. expired June 2015. Month later, they took money in my account. When I fone they said i must go to the shop and fill the cancellation form. I did, on the 24/08/2015. Case number was ***6.they keept on taking money on my account until November I went back to the shop. They gave me new case number. ***0. November moth end they took money again and December. they are taking more than R900 and the account agreement was for R399 per month . Now l went back to the shop they gave me new case number ***5. Third one still not sorted. Please help i need my money back.