I had the same issue ("1000/35" with Xfinity but in reality it was barely 10/1) but keep checking because CenturyLink is regularly bringing fiber to new areas. For the same price I can get 1000/1000 symmetric now.
All of my neighboring blocks have 1g/1g from them, but the most they offer at my address is a 40/40 "fiber-based coax" internet that I'm probably not even wired for. I would love for that to change - my DOCSIS internet has been pretty solid, but I miss the gigabit upload.