Ridiculous billing

I had an account handed over to Viljoen Attorneys, I arranged monthly payment with them and loaded the payment as a debit order on my bank account. Each month they would phone me to confirm that they received a payment and request the next payment date. I explained to them that it is on debit order yet they kept phoning me. I now received a statement where they charged me R 221 for phone calls, my final payment is only R 147. I sent a mail to ask for a credit and refund on the calls and was met met an sms that said that if I don't make payment they will blacklist me<br> <br> I feel that this is ******ion and an abuse of power. Added to this the statement clearly states that any further communication will be added to my account, thus by querying a statement I will be charged an additional amount, this is not in line with the CPA or any other legislation. <br> <br> The amounts are not big but the principal of the matter remains , you can get away with anything you want if the amount will be less than legal costs to dispute it.