Poor service in high grade

I need to settle/terminate contract with immediate effect the service is highly poor. Called telkom early in September to change debit order date they said it can only be changed for October month I said ok i will make sure that month of September there is enough funds... I phoned again first week of October to check if date is changed to the 15th they said it wasn't... And I had to make sure that there are enough funds in my account end of October I told the lady that this is telkom's fault because of of their staff members said is been changed now yesterday there wasn't enough funds in my account and this morning I was planning to make an eft/immediate payment they are telling me that there will be penalty fee of 202 because of late payment I how can you charge lot of money after trying so Hard To make payment in time? On the right date? Now I want settle it I spoke to nonhlanhla she said she cannot assist, I phoned again I spoke to nthabiseng she hanged a phone while waiting for settlement amount. Help me to cancel this account M sick and tired of following service provider as if m not a customer