Unhappy, angry and disappointed

Wow what a pathetic service i got today. I went to dstv self service to review how much i need to pay for the next month and i got the shock of my life, saw that i needed to pay R 743 yet my product is not that much, i called in 3times today and all call centre agents failed to explain why i am paying so much and every time i am put on hold until it says call ended. I asked to speak tp the manager, i was told his coming i must hold on and my call was ended again what makese more angry is the fact that i calling with my airtime and i am seeking help and they dont have the decency to call back atleast. I was told i need to pay that amount because there was a discount i was given in march and april and now i must pay that difference? What nonsense is this??? I am very angry and disappointed