I've researched well into this and think i know the answer but a very brief overview;
The girlfriend has received 2 letters at her parents' address (formal demand and notice of impending action) from Past Due. They're standard letter formats.
The debt amount is fairly small but in three figures with a service provider (TV/broadband etc) whom she cancelled the contract with around 3 / 4 years ago. At the time she cancelled informing them that she was leaving a relationship and also that address. They advised that the account was settled and that she could cancel the DD (verbally, we have no written evidence) - which she did. We are assuming the debt is for the previous address but can't be 100% certain without further evidence.
She doesn't know how they found her and is obviously very concerned by the whole thing. As are her parents.
I see a few options;
1) standard 'prove it' letter
2) ring Sky to get further info
3) ignore the whole thing for now (ideally not this option as her folks will go mental).
Thoughts on the best way to proceed? We're going to check her credit report tomorrow. As another note they have spelled her first name incorrectly. I'm not sure if this has any bearing though.