Struggle to CANCEL my contract

The service are very poor, I am trying to cancel and every time they say they will investigate and give me feedback. They don't call me back and i need to use my money and time to call them to solve this problem. They keep on sending me to after care and back to cancelations. No one there knows what to do. I am still waiting for the playback of my cancelation and they don't even get back to me to explain what is happening. I just want to cancel. I did my 2 years and don't want to continue.