Bad service from telkom

I had two contract with Telkom the first is for cellphone and finish it end of march then I cancelled it 7 April of which I didn't know that I have to cancel it because is finish but only to find out that they send me an invoice that I must pay money because they continue giving me data without my permission,so the other contract is for router the router had network problem and phoned them they said they can help me after 6 months ,the I ask what must I do with it because doesn't have coverage,the said I must cancel the contract they won't charge me for penalty fee but now I received invoice showing that I must pay penalty fee and monthly instalment while the contract is cancelled