Account exchange

hi, I have a problem. i was on level 1994 with a lot of boosters and messages when, I don't know how, the app synchronized with another fb account of a friend who used my ipad and used facebook on the browser (the fb app was on my account)a few days before. Now his account has my booster, and my account is still at level 1994 even if I get to 1996 and, most important, I lost all of my booster and I have no idea on how to get them back. The "wrong" account is Sam Setter, now on level 1996. Can you help me please?