Cell C debiting my *** instead of R79

2 months back i took two contracts (Router and pre-owned iphone 5s) with cell c and the agreement i had with them was R79 on the router and was going to get 1 GB during the day and 2 GB at night. The second contract i agreed to pay R279 for a pre-owned iphone and i am getting R100 rand airtime in return. They 1st delivered the router and then after months of fighting i got the cell phone. The first debit for the router was about R115 which is fine to me because it was delivered half-way through the month and they told me pro rata app**** and now for the second month they are debiting me about R2 400 on the router and from what i know i agreed on a R79 fixed contract with them. I am sick and tired of Cell C, i called their help line and the person with an attitude was assisting me told me i have an open contract with cell c of which i never requested. I also found out that they have their own extra limit again on the cell phone. This is simple for Me the contract i agreed on with cell c is not the contract i have with cell c. Cell c is just **** and i wont pay for the contract i did not agree on. When you call their customer care you are surely just ruining your day.