Re: Bluetooth Hacked, help
Hard to know for sure. The best course of action at this point would be to do a factory data reset. Before you do so, go to Settings>Backup & Reset, and uncheck "Automatically Restore," which will prevent apps from automatically reinstalling (in case the alleged culprit might have remotely installed some kind of malicious app on your phone). The factory reset will, of course, wipe your phone, so backup or sync any important information.
As for any sensitive information that could have possibly been compromised, I would advise you just to keep a close eye on your credit card accounts and bank accounts for any suspicious activities. It's probably premature to cancel any cards at this point.