Worst place to ever do matric

The first month I have enrolled with Intec, they never submitted my debit order, 2 months ago I changed from a savings account to a cheque account, spoke to someone to change the debit order. So my May debit order went off with no money in the account, so end of May the sended me a sms to state that I didn't pay my Intec, so I phoned and Themdla told me to pay R713 so that my account is up to date. And I must email her the proof of payment with my new banking details. She told me that I have to cancelled the debit order and she will cancel the debit order from their side. So Tuesday I received a sms that i didn't pay my arrears. Today I phoned Themdla again, as I was under the impression now my account will be updated. But no now I have to pay R100 extra just because my debit order bounced? How many times must I ask them to change my bank details and how much more must I pay for their mistake? And then their staff is so rude, tell me that I have to pay the R100 and then drop the phone? Sies wish I never enrolled with Intec