CONTRACT CANCELLATION NOT PROCESSED

I had a month-to-month home router contract which was offered to me online and was delivered to me which I was not happy with and decided to cancell the contract at the MTN Store at Pinecrest Centre where I returned the router and was assured that the contract cancellation had been processed. To my surprise MTN is still debiting my back account and when I query between call center cancellation department and the store I am not getting assistance I am being refered from pillar to post!!!!!!!!!!!!!!! MTN IS THE WORST SERVICE PROVIDER WILL NOT USE THEM OR REFER THEM TO ANY OF MY FAMILY OR FRIENDS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!