First off did you contact Stardock? If not then do so. Do you have anything running in the background, or is any one else on your network? These have cause issue for mean, as in a really high unstable ping.
Closing background programs that connect to the internet, and not haveing anyone else on you internet connection sonve my ping issues, maybe it will help you. If not Stardock offers 1 on 1 problem solving.
And if you wonder who these people are that have never had any issues with the game, I consider myself one of those people. I forwarded my port, and did the above, and as a result have had no issues, even 5v5s.