What happens with these things (apart from what PePiPoo says) is that debts are batched up and then offered for sale to other debt collection agencies. These then sift through them, trying to isolate the goodies from the wastes-of-time. Everyone normally gets three letters and three calls and then if they're unsuccessful, it goes back to the client, who tries again with some other DCA.
Rossendales have considerable form for this, as do Arrow Global. Whatever else you do, DON'T acknowledge the debt, TELL them if the debt is more than 6 years old, that it is unenforceable (but still don't acknowledge the debt is yours, and DON'T get into any exchange of letters.
They also all have form for trying to use reverse-searches on the Phone Book, Voters' Roll and DVLA, so you may get calls or letters "on spec" if your details match the dastardly beast who overstayed in a car park because it was late at night and "you" were too tired to continue.
If you are not the person concerned, immediately threaten them with (1) personal "visits" to their office with the Police to arrest those responsible or (2) that you will do your best to get their CCL revoked or suspended (this one works best). I was the subject of an identity fraud a long time ago, and a very polite insistence that the company would be having problems with the continuance of their CCL worked wonders. It is a CRIMINAL offence to attempt to collect a debt if the company knows you are not the debtor.
Don't lose any sleep about it, unless it's an official ticket from a council or other scummy busybody.
