Try to use bridges instead relays.
These are to much hard to indentify as tor relays because they aren't announced and listed in the main Tor directory.
here's the guide:
https://www.torproject.org/docs/bridges
Tell me if it works...
My ISP blocks a lot of tor relays and with bridges my problems are gone... This are too usefull when you are under these conditions, that is the case of countries like China, and North Korea.