Not getting what you are paying for and no one will assist

I have a 100mb/100mb line and do not even get 20/20. Every time I contact them to try downgrade line because I am not getting what I am paying for, no one can assist and I get moved to pillar to post. This is ridiculous! Try to email them, you cant, no support customer email available. The app gives me errors. I am stuck paying for a service I dont get.