Is there anything that they can be prosecuted for?

I got a letter about "Scooter - Jumping all over the world" this morning too, demanding £500.04. They claim the downloading date was 12/05/08 and then later say the album was released 10/10/08, 5 months after I (allegedly) downloaded it! Surely there must be something we can do more than just complaining? Can they be sued for extorsion or illegally obtaining details (name, address etc)? I've no idea about the legal side of this stuff but there must be someone on here who knows? I'm not bothered about money I just want to screw them over -Edit- My ISP is Be Broadband - I only started service with them 05/2008 so I'm trying to find out an exact date of when it went live. -Edit- According to the woman at Be my line went live on 12/05/2008, same date that they're claiming on the letter. However my first invoice states the 14th. Also, there's no comments or marks on my account about anyone requeting my details.