my husband received a message on his phone with the fbi logo stating that he needed to pay 500 dollars within 24 hrs with a pay pal card for some investigation to be done and they would return 400 of it within 48 hrs if not then his phone would be blocked. this happened two days ago and ever since his phone is locked where the home screen is now a fbi case number. can you tell me what we need to do to fix this. on the messages he got there was no contact info at all