Activation lock is telling me to log into nonexistent iCloud email

I forgot the passcode to my iPhone. I tried different combinations to see if it was right. My iPhone got disabled and it said connect to iTunes. I took my iPhone to the Apple Store at Cumberland Mall in Atlanta and they did something to my iPhone! Now it says Activation Lock and its telling me to enter in my Apple ID (which is an iCloud email for some reason) and password. It says the password is wrong and birthday security question is wrong. When I look up with email, it says that it doesn't exist. I even tried to sign up with the same iCloud email and it says that it's already taken?????? PLEASE HELP!