sales assistant

I have an contract with telkom,the time i open it they didn't tell me about the insurance within 7days after a month i wanted insurance they said they can't help,i was supposed to take it before 7days now the contact said i must pay 489 now they they more than that they say always when they want to do take a debit order it bounce now they deduct 701,when i ask i leave the money in the bank until still they don't deduct now they blame me for not taking money as we agreed on,i asked them since you can't deduct as we agreed,less stop the debit order i will pay in cash they say is impossible for them to do that,im so disappointed with there service they have solutions only problems,now is like im the bad person this it affects my credit card even me financially i won't be paying R701 instead of R489 in our agreement...