Taking money and blocking my phone

I Have paid my phone account every month and December Telkom didn't allocate the debited amount to my account after they debited it from my account. I have send them various email with my bank statements showing that the amount was paid and eventually it got resolved and they debited my account on the 01st of February with the correct amount. On the 16th of February they ceased my account due to non payment. I have been having this problem every month with Telkom and is getting sick and tired of it