unprofessional Service

Good Day<br> <br> on the 29th of January 2016, I paid my account R550 and on the 10th February 2016 I received a message that I must pay my account and I called RSC and explained that I have paid they advice me to send proof of payment, I immediately send the proof and on the 11th I called to check if they received my documents they confirmed and assured me that it will be sorted within 48 hours even today they are still sorting it and now the have included interest charges and put my account on arrears and I have been sending follow up emails but I am not getting any joy from this...they are not even calling me to apologise for that.....