Unhappy customer

I am writing with a broken heart as i was called to subscribe for the price lock and was told that I will be paying R500 and now I have already paid R20000 for the only 2 months. I have called customer care they kept on saying they fixing my problem with no success as now when I check my balance is R845. And no one can explain it to me. I have paid two months forward but I am still behind. I regret taking their package and also very angry because I have used my airtime and travelled to dtsv with still no explanation and they say I must again call price lock which the phone was dropped in my ears today when I was transferred to understand what is happening.