Compliant

I'm on a 24 months contract with cell c paying R300 a month even though the amount comes around R304.99 Whats the big deal I still pay however seems as if they don't know how to treat customers today I received a sms stating I will be billed a amount of R610.99 is that fair yet I don't even use the simcard for anything I think someone needs to fine this organization we can't even query or pay cash in stores cause they useless I signed a contract that shows I will pay R300 a month on a 24 months yet over billed for the first time my number for the cell c contract is *** but I swear I won't do any upgrades or any sort of thing because I feel they don't know what making they clients happy is about