Bad service

I have upgraded my dstv from 50gb to 400gb its been 2 months paying but still receiving 50gb. Its worse this month I didn't get any data. I wanted to cancel but I've been told I need to pay the cancellation fee. So what am I supposed to do if I m not happy with what m paying for. this is really unfair. Every time the agents say they will escalate yoooo for 2 months hhai no its too much.