Terrible call center service and agents are rude!!

The call center service is terrible!! The agents are rude and very short tempered... I called 3 times already and got 3 different agents and still I don't know why my settlement amount is so high. I pay every month and the total outstanding amount has only gone down by about R900 in 6 months!! That's ridiculous!! Been sent back and forth between customer service and collections department, my airtime has been wasted and I still don't have an answer. I called the branch as well and they said I must call the call center.