Impact meters does not read meters and charges exorbitant bills from consumers

My electricity bill with impact meters goes up every month without any proof of the usage. I leave alone and I am hardly at home during the day as I work . I do not cook every day and I use electricity sparingly .July R 566. 07. August R 677. 37 and I just received a bill of R 872. 65 and every time I request to be sent detailed consumption bill , I am told by Impact meters that they cannot send me the detailed bill and that I should come to their office to view the bill and that they will not refund my petrol for commuting to them. Impact meters does not read the electricity meter, they use the average usage in the complex.