Bad Service provider.

I Sign up for 5G service on August this and the delivery a router with 5G simcard at my work since that day until to date I've never use that service because it not provide connection, I call them daily to inform them about the issue but they was no solution then I decided to cancel they service and requested for more service they informed me that it will cancel Month end of September but it never did because every month the are debting R500 from my account and they are refusing to refund me. I am really tired of this issue because now I am paying for something I am not using. Please assist me