How do you contact tech support. My issue with two accounts, seperate keys in same home is annoying

I uninstalled my game thinking that might be it. he was in playing and I went back in, put my key in and it thinks I am him. Whoever logs in second, with their OWN KEY, takes the username as the other person. It will not allow us in the same games and if someone is already in one it will kick them o...

My roommate and I both downloaded the standalone version of the game last week and paid for our own keys. Everything worked fine. This week when I got home I logged in and went to create a server for us to play. It would not let him join in. In fact in any game we could not join in together. We then...