Firstly you need to clarify what the ticket is. Are NCP operating the car park on behalf of the local authority? Is the fine marked as a "Penalty Charge Notice" or a "Parking Charge Notice"?

If it's a "Penalty Charge Notice" you need to either appeal or stump up the money and pay the fine or they will come gunning for you and have the power to do so.

If it's a "Parking Charge Notice" throw it away and ignore all correspondence.

It's imperitive you find out with which you have been issued