Authorised Debit Order not gone through!

Telkom debit orders are inconsistent. I have given a debit order mandate to run through my account every month on the 20th. This was done up to November, then suddenly in December someone decided to sip ****tails and not do their job. The debit order in December was not even attempted to say the least. I would like to believe this is but my fault as Telkom’s money is still sitting in my account waiting for them to debit. Today, I received sms’s to say my account is handed over to collections! Handed over? When it was their sloppy mess not to debit the account? I’m still trying to understand why is Telkom not accountable for their stupid errors? I then contacted the call centre only to find a rude call agent by the name of Ntakadzeni Mudau who barely could assist with the query. I requested for her team leader to assist me instead seeming that she had very little knowledge about my query and she told me she was not available, she will call by end of day. I’m still waiting for that call! Clearly nobody in the finance department wants to take accountability of this mess they have created. Can I have this matter escalated ASAP! In fact I would like to settle and close this account effective immediately!