Unauthorised deduction of funds

I am so frustrated and disgusted with Cell C at the moment. I have been a client for many years but have never received such shocking service. I upgraded a contract at Makro Alberton in November 2015. At the time I requested the account to be capped. By February 2016 my data sim was not working anymore. I took it to a store and was informed that the sim is not covered under warranty and I need to pay for a sim swap. The fact that they wanted me to pay for faulty equipment was very infuriating. I refused and never used the data sim for a year. In February 2017 I eventually re-activated the data sim and was informed that the data for the last year has been forfeited. How dare you! This is data that I paid for every month and was never using, how dare you tell me it's gone??? To top things off, for about 5 months since February, I get slapped with an extra R200 on my bill every month for "out of bundle data charges"??? How can you be deducting money for anything other than the subscription on a capped account???? I want the funds refunded as of the beginning of 2017 and I want my data re-imbursed for the year not in use that I paid for. If you are not willing to do so, I will be forced to take further action.