Stop debiting my account

When I complained that you debit my account without me having an account with you, your response was that all my accounts with you are closed. However, this month, like you always does, debited my account. Please stop that practice because my account with you ended in March 2015 and I have asked you numerous times to cancel it. I will never ever take an account with MTN because it does not end even after its 24 months and continues even when I let you know that it should end.