Samsung Grand Prime verify the original gmail on device.

[AC Question]

The phone is locked and customer can't use phone at all until 72 hours??? Help

 

[Rukbat]

That sounds like a virus. Two solutions I can think of:

1. Wait 72 hours. Back the device up. Reflash the stock ROM.

2. Reflash the stock ROM now and lose all the customer's data.

Once you get it fixed, install a good antivirus app and Malwarebytes, to prevent it from happening again.