Extremely high ping in-game, out of game ping is fine.

[Priya]

Is this something I should try and contact Level 3 at, or something? Or get my own ISP involved to try and contact them?

Do both. The more people we can get involved the better. You seem to be hitting a funky Montreal node which isn't uncommon.

Level3 works with companies, so you would probably do better to get your ISP involved if possible. It would solve your problem if your ISP will route you around it but not the problem at large. There's a contact form for Level3 here http://www.level3.com/en/forms/contactus_prim/ where you can let them know the IP/trace info/etc of the problem node. They ask for company information, but you can just throw N/A in there. We don't really have any other way (besides phone) to contact Level3. Your ISP might be willing to do it for you; people are seeing different levels of ISP helpfulness with this.