And fictional/wrong debts too.
My parents had a HCEO push a letter through the door saying I'll be back later to take the car. Cue frantic phonecalls/traces to find that a) they didn't owe any debt and b) the company had just gone through the electoral role and checked the addresses to find the same name with the most expensive car.
My debts however were real and are now statute barred (6 years+), though I learnt lots of the nasty underhanded tricks they pull and now have a handy list for others to follow :-
Always ask for proof of the debt.... many have none, so it could be fictitious (had 2 of those in a year)
If they try and get you to sign ANYTHING refuse, whatever they say the reason it's most likely a lie to get you to sign a walk-in possession
never let them in, speak on the front.... sure it's embarassing but one foot in the door means they OWN everything in sight (except beds/cooker/essentials).
Most importantly never, ever agree a payment until you have concrete proof of the debt (from them). a single "token" payment restarts the 6 year statute limit.
Oh and keep as much as possible in writing.... voice isn't worth the paper it's written on :)