I've reinstalled the game since I wanted to have the possibility to watch ads to get lives (just like my bf does!). Spoiler: Did not work!
After re-installing and signing in with facebook, my level was correct and I still had my friends but what is really upsetting: all my boosters are gone! I would like them back, please! I played a lot to get those and there was no warning whatsoever anywhere in the process that that could happen!
Thanks for your support! vegastini