This happened to me. I prestiged then logged off. The next time I got on I noticed I did not receive a token for reaching 2nd prestige. I am now level 50 and I still don't have the token. I have tried multiple times to get help from customer support via chat and it seems like they won't do shit for you but they do realize there is a problem. Basically don't prestige unless you are going to play a couple of games after you prestige. They said something like it didn't save to the server since my connection was terminated(this didn't make sense to me since I signed off normally). It sucks dick though, I am going to fight it though and try to get my token, I already feel like I spent too much money on this laggy version of MW2, I am not getting screwed over on prestige tokens too! It's not my fault that IW has shit servers. Also sorry for wall of text but they tried to tell me that lag in game is not their server's problem!

TLDR: Play a game before you sign out after you prestige to avoid shitty servers not realizing the fact that you prestiged and awarding you a token.