I have experienced a similar problem. have you ever linked another Google account (ie Google Voice, G+,...) or anything like Facebook or Hotmail to your Google account? If so try accessing your contacts via that account. when Google was experiencing sync problems in the past I found ALL of my contacts, new, ancient and forgotten had been automatically synced to my old (and expired) att.net account. I discovered this when I pulled an old laptop out in order to donate it -luckily on the same day that all my contacts and calender INFO were lost forever!
I was checking the "workings" of the laptop and getting ready to wipe the HD when I accidentally opened the e mail program and saw that the contacts showed to be updated! first time I beat Murphy's Law. I contacted Google's Email HELP forum and was told that a "partial sync" had happened and that was the only account that Sync had completed..
Anyway - It would be worth a try, good luck and Back up!