billing

<p>I have contract with cell c for a mordem and sim which i receive monthly data of 1Gb.i hardly use the sim but am surprised they always charge me more.the agreed amount which i should pay is R69.I now have 994,73 data and 2048 midnight data,and it says my current usage is R1;50 of which i dont understand why i am charged that R1,50 because i still have unused data and i dont make calls with the sim card,even last month i was chgarged R1,50 now the payment for month end is R72.41.why is cellc charging me mor because am only using the data which they load every month and i hv never exceeded.even when they load data on the 1st i still hv data remaining frm previous month which cannot be carried over.i never make calls or go through the internet without data,i have another top up contract with cellc which am happy with but with the data contract i am highly disappointed.</p>