REGRET!!!!

I was offered to upgrade early - With no additional fees - Now my service is suspended because theres an amount outstanding which was confirmed is the early upgrade fee - I made sure with the call centre agent that there isnt any fees but to my surprise - Now i get an sms saying my im going to pay R71 for something im not aware of. You call the callcentre and their systems are down for over a week now - How am i supposed to resolve this nonsense - The branch guys just blame the callcentre guys and dont assist