Aggressive Creditworx staff who can't give clarity

So fed up with this company and their rude agents. I made an arrangement to settle a 3 year old account, which I didn't agree with in the first place. If I remember correctly it was a little over R100, and when Creditworx phoned me to make an arrangement suddenly the amount was R620 to settle the account. I Settled the account, though the second Payement was late. They subsequently phoned me the next day to tell me the account was R110 outstanding, but I paid the full amount, I did not agree to pay the additional amount as there was no notice or correspondence about the additional amount added to my settlement. 3 days later and extremely rude woman phoned me to tell me that the outstanding amount was now R155????? hello what for? I asked her what percentage interest was being charge and why the amount it R45 up in 3 days? she couldn't answer me properly, I asked to speak to her supervisor, at which time she got very annoyed told me her supervisor was busy and she was in charge of this account. Again I asked for an explanation and what percentage interest this company charges, because I will not agree to payment until I get clarification. I asked for her supervisor to phone me when they are available at which point she proceeded to aggressively tell me how soon I will be phoning her back begging to pay the account.... and then hung up.

Shocking, shocking, shocking.