The Activision website has that "fix corruption tool" which im assuming is as broken as this most recent Call of Duty. SO I had no luck there. I logged in not even 24 hours after my last interaction with the game only to find my stats all rest and back to level 1. Would really love to have this restored.
Hi there, bro. You can try and request for an account check on your account for Ghosts via this link: http://support.activision.com/articles/en_US/FAQ/My-Call-of-Duty-Ghosts-Stats-Have-Been-Reset/
The response may take some time but once you submit the form, your case would be looked at by the right parties. I mean, my friend also had a similar concern and he also submitted the form and that he got a response after waiting it out for a bit. I'm not really certain about the timeframe though.
Well. My guess is that you have been part of modded lobby (intentional or not).
If you have had your stats boosted in multiplayer or extinction = reset of all your stats.
A support case was created for you and you should be contacted shortly by a Customer Support Representative, if you haven't been already. You can view and update your case at the Activision Support website. After logging in, go to "My Support" then "My Cases".