Horrible service

I'm very disappointed with cell c i have too contracts with them ,I had a query in March where my monthly debit order increased with no explanation.I called in and they advised me that they will contact me,no one got back to me,i called in again and told them if my query is not resolved i'm not going to pay,still no one got back to me.I didn't pay for 2 months.I called again and was told my query was closed without being resolved.I was very upset they opened another query for investigation because my contract is ending in July i made an arrangement to pay that outstanding amount because I don't want anything to do with cell c.I made arrangements and called them that i don't want to continue with them contract since it will be ending soon,I was advised that they can't cancel my contract.Meaning i will still be paying for something I don't want.