Telkoms bad service

I upgraded my contract with telkom and the person who was assisting me said I had to pay R1500 for the mobile device i upgraded because I was upgrading months early. They said i could pay it over 7 months until it is paid off but I said they could debit it all at once with my monthly payment. They didn't debit when the month ended and sent an invoice tha they were going to debit the R1500 end of March, I had no problem with that but today i woke up and all my 3 of my cards had been suspended, when I called the agent said it was because of the money they had not debited. I asked why they suspended my services when I had made sure that my account had the funds but they were the ones who chose not to collect, I need that data for my schook work & she said there's nothing she can do, I'll have to wait until they have debited. Today's the 16th, I can't wait the whole month and not be able to use my cards. They said they can give me banking details so I can make a payment, I get paid on the 25th, I don't have the money right now. I want them to resume my services because I have work that needs to be submitted & it isn't my fault that they didn't collect. The person who was assisting me with the upgrade did not tell me that this might happen, she said I should make sure that the funds are there and I did.