T-Mobile Lied about 3 & 4 G service in my area . Paying to be on everyone else s WiFi, Internet

when I signed for internet on my phone plus 2 other phones , I was told we had 4g here . Well needless to say we have nothing ..99.9% of the time if WI-FI isn't around I can't get on the internet. The straw that broke the camels back was when my internet went down at home and I needed to look Centurylink's number... Guess What? You Guessed I couldn't get on because my internet was down on my home computer  . I am in a 2 year Contract with them and I don't think I should have to pay for something that I am not receiving the service on .. I pay $40 extra a month for internet that I don't need because it doesn't work .. I been on the phone with them several times about this and all they can say is i am in a contract and there is nothing they can do about it  . I want out of my Contract. Can you help ? Thanks