Cell C is a total *******!!!People should avoid it

Hi, i have a contract with Cell C for a laptop and a 2gig data which i pay 300rand monthly for. I am experiencing a problem with them with their billing every month which i think its a *******. I just checked my data balance and it reflected 900mb left whereele on their side it reflects only 5kb left. I called the call center to ask about that and the guy just hung up on me when i told him that they dont have transparency as they charge differently behind the scenes. And to my surprise i just found out that for January i will be debited 550rands wherelse i didnt even finish all my data so i dont know what i am being charged foe. This is not the firsttime thi is happening, i am getting overcharged almotevery month and this has to come to an end, i need to be refunded all the money i have been ********** or else i am going straight to the CPA to take the matter far and will make sure i stop all people associated with me from using its services