Before Verizon will unlock it for you, it must be currently active on a Verizon plan. The plan must have been active for at least 6 months.
It would probably be easiest if your friend activated it on his Verizon account, I assume he has one, and then have Verizon unlock it.
There is nothing you can do. Verizon WILL NOT unlock it for you UNLESS it is currently active on a Verizon plan. You should try to get your money back.
Edit: or you could try to sell it to someone who CAN use it.