Suggest writing directly to UKCPS asking for evidence, as you do no recall using the car park mentioned and have had no previous contact regarding any alleged fine.

Important to keep a copy of the letter and to send by recorded. These companies send out these invoices for these private parking issues, but they do not always pursue. Still you cannot ignore and need to write to them asking for their evidence.

Hi,

I have received a letter from debt recovery agency "Court proceedings limited London" for debt regarding parking fine on private land. The fine is of £120 and is regarding overstaying at car park on 22 Oct 2012. I have never received any notice from parking company (UKCPS) neither do I recall if I have parked there on that day. The letter is a surprise for me. Should I talk directly to the parking company and inquire about it or the debt recovery company? Can I challenge this parking fine or complain about it? What is the best way to deal with it as this is the first time I am faced with such an issue.

Thanks