Ripped off by a friend.

[Metric.]

[louder]

I bought this MP3 player off of my "friend" today for £10, it worked well so i was rather pleased until i came on to my pc to put music on it, i tried deleting the rubbish they had on it, but it wouldn't let me.. fine i thought, i'll delete it from the actual MP3 player later, but then i tried putting music on it and again it won't let me put anything on it, unless i record it from somewhere. It asks for a disk, but my the person i bought it from never gave me a disk.. And now i hear that it could possibly be stolen.. And the person said they "bought" it recently. But if it was stolen, they won't have the disk for it.. Any ideas on what i can do?

knock him out. lmao.