MTN ********LY DEDUCTING ON MY ACCOUNT

Hi, I took a contract with Mtn via rewardsco, i canceled it when i couldnt connect to the wifi and after struggling with MTN. i canceled it within the 7 days cooling period. Rewardsco confirms that the router was received and contract canceled. But MTN keept deducting money on my account today they deducted R3236.97.. I need mtn to remove me from their records as i do not owe them anything