Cell c does not care

On the 1 August 2017 I received a bill that was R900 more than my contract for my I pad. this I pad does not have any signal on my farm. The agents forgot to add my limit on my contract and billed me much more for 2 days when we were in the city. All my data expires every other month as we do not have any signal on our farm, but when we bought the contract they promised we would have signal. When I bought the contract from Cell c they said I would have great signal on my farm because my vodacom contract has 3 g signal. from the first day we did not get any connection, I have asked Cell c for a signal booster as we took out more than 2 contracts from them. Everytime I phone and complain they say they will come back to me. This was on the 18 Aug 2016, 6 sep 2016 1 Feb 2017 5 June 2017 and again on the 1 Aug 2017. I do not get any reply from them in connection with my bad signal or my account that was over billed. This is the poorest service I have ever received from any cellphone company.