Question Author
Well that's strange, I came back to thank you all and my question had disappeared!
Anyway I've looked through your links and tried to contact them (that's jumping through hoops!) and eventually rang them. The email is genuine. They apologised for the length of time getting in touch but said this is not unusual, yeah right. They were very nice except they kept telling me it would probably affect my credit score if I didn't pay. Since it is just under £20 I'm very tempted to not pay. Nah, not really, I just want rid of them.
So, thanks all.