Bank account details captured wrongly

Took out a data contract with Mobile store and my account was never debited for the whole of last year, when I was finally told to query the issue with Telkom by Mobilestore I found out that someone from Telkom captured my banking details wrong which resulted in Telkom not debiting my account for months. Now im being told that my account is being handed over because of lack of payment when the issue was telkom for capturing wrong details. I’ve been calling telkom numerous times to fix the issue only for my calls to get cut off before resolving my matter. Im annoyed and irritated and considering to never ever take out a contract with Mobile store and Telkom.