Increased bill - I want answers!

I cant carry on like this. Monthly I am having to call Telkom regarding my huge and incorrect bill. I am being billed for items that I should not be billed for. I did not ask for a new router and I was billed for one, last month I called and was told this would be sorted out. Telkom you are now messing with my credit rating because I cant afford to pay these bills of R2300, I dont even know what I am paying for. My contract was R800 a month and then that increased without notification due to some installation (which by the way is against the law) now I have to sit with some huge bill for I dont know what. Please get my billing right. I dont have time to call every month only to have nothing ever changed, instead things get worse, I also am getting changed a late fee every month BUT I AM TRYING TO SORT OUT YOUR ISSUES before I pay. I agreed to a contract and Telkom you are not sticking to that, so either you stick to it or cancel it and I can go to a service provider with integrity that treats their customers fairly. Please get back to me and let me know if the contract is void because you broke agreement or if you are going to correct my bill so I can pay you and even get charged a late fee!