Data Usage

I took out a Wi-Fi contract with Telkom in July 2017 , we received the device within 3 days the data was finish. I left it and this month I tested it by only allowing my mother to use the Wifi her she used only 200MB as on her phone data usage. I contact Telkom to ask what is happening with this contract and was told that the data usage on a smart phone is not correct. The guy requested a detailed report of data used and I was told that this was used by sessions that was opened etc . I want to cancel my contract with immediate and was told that I need to pay the remainder of the contract. Telkom is one of the biggest telecommunication companies in South Africa but the service and data usage is pathetic. I want my contract to be cancelled and no penalties to be charged as this is bad service given from the company and not because I do not want to use the service. Telkom needs to be take responsibility for this invalid data usage and they don’t. There was not assistance from them in trying to solve this all they said was you used it, not we will investigate etc