How to unlock the activation lock?
A few days ago, I logged into someone else's icloud (the person with this account claimed that he/she was a friend of my friend & asked for my help because he/she lost his/her mobile phone). After I logged in, that person immediately changed his password and set it to LOST MODE. My iphone is now locked with activation lock and it says on the lock screen "give me 300 dollars or the consequences are at your own risk. Call me xxx-xxx-xxx"
I went to the Genius Bar in Apple Store, and they told me to wait for the updated email in 24 hours. There are no new messages for now after 5 days.