[Unregistered]

I have Samsung Galaxy S3. The device is encrypted.
Something crazy happened! I do NOT turn on Bluetooth and if I did my device is invisible. But somehow a device called "Deborah's iPhone" requested to pair with my device and I was distracted and unsure of what was happening so I accepted the pair. That day my icons on my main screen duplicated and changed position, the "clock" app opened on its own, and AVG Antivirus registered that I have 1 threat (system manager application), though that could be unrelated.
WHAT HAPPENED AND HOW???
What files could have been stolen from my phone, if any?
The night before this happened I asked a man who is literally obsessed with me to stop harrassing me and he lives in a "hacker house." Suspicious??!
I'd appreciate any thoughts. T-mobile tech support was useless in this instance. Thanks.

[B. Diddy]

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.