Breach of contract

I took out a contract for home internet for 24 months. This contract stopped the last day of March 2017. The service was stopped at that time but the part?????of the contract still kept on going off monthly. ( R630 down to R399). No service was received from them for this time as the contract still in my possession stated that it stopped at the end of March 2017. I have received no mails or information from Telkom from the first day of the contract. When I discovered the money is still going off after 10 months I contacted the 081180 number. After 14 times, I talked to a person who said I have to cancel the contract by means of a cancelation form. ( I don't know why I need this as I have a written contract stating I have a24 month contract). For the last 4 days I have talked to 3 different people all promising me to forward the cancelation form, but until now, I have not received any forms. I have tried to talk to the same person every time, but apparently they don't know each other. I have lost R4000 and for a week I still can not get this order of my name. Phoned them 3 times today(08/02/2018). Total of 34 minutes on the line with no answer. This is definitely a company taking money for nothing and has the worst service ever.