Debit Order authorised and Data locked

I took up a DATA contract with MTN, i authorized a debit order for the 20th every month, but for the past month i have to be the one inconvinience, because if they dont debit my account they block my account from accessing data then they want me to pay for the data i could not use because they blocked it. i have wrote too many emails for them to fix this issue. As i write this they did not debit my account Oct the 20th, and blocked me from accessing data. When i write an email i am told my account is in arrears for the debit order that was unpaid, and i owe for the Oct month and current. Mind you they blocked my account from accessing data. So what exactly am i paying for. Fix you systems and unlock my account, otherwise cancel that contract.