Getting Dial-Up speed for Premium Cost

So, we pay for Premium 100Mbps and I am lucky to max at 20Mbps, constant internet drops throughout the day. And, as I was reading the paperwork, I read that in the paperwork that we "get up to 100Mbps" oh, so paying over $100 for maybe 20Mbps is what it really is then? Why not just put that? $100 for up to 20Mbps, then I could have decided if that is what I really wanted to spend on such slow speed. How many people actually deal with these low speeds for such a high price? Can I get out of contract for Cox not providing what the representative said I was getting, she never said "up to 100Mbps" she said "You get 100Mbps". This is just really frustrating, and a huge rip off.