I've officially lost all hope in Telkom

How you guys manage to ***** up consistently is beyond me. After I wasn't debited last month and wrote a report here I was contacted by Mogaugelwa Makofane who is the HVC Billing Specialist, I had a lot of concerns but we reached an agreement that I will pay last months fee and they debit me normally for this months fee, I had concerns Id be double debited because it's happened before, but she advised I wouldnt.I paid R400 for last months non debit on Tuesday 8-12-15,I emailed her the proof of payment on Wednesday 9-12-15, she sent an email to the billing department. Today 11-12-15 I was debited R799,20 which is for last months non debit plus this months fee after paying the R400 from last month. Secondly who gives you the right to debit my account when it suits you because my agreement is that I am debited on the 30th of every month! Now it's clear that there's a huge problem with your system and employees, someone or some department is not doing their job. I'm sick and tired of having to deal with Telkom nonsense every month, I'm at the point where I want out of this contract and I wouldn't advise anyone to join Telkom because really your service delivery is something else.