To be a valid ticket it must contain the following information; ticket reference number, vehicle reg no, vehicle make and colour, location, date and time of offence, attendant/warden no, contravention code & description and penalty including early settlement discount. If the ticket is a fixed penalty notice FPN then it has been issued by a traffic warden or police officer and you will have little recourse. However if it is a penalty charge notice PCN this will have been issued by a local council parking attendant and if the information listed above is incorrect in any way you should appeal politely in writing to the adjudication board for the council who issued it.
As a piece of advice, if you ever get done for being late back to your car, simply wait for the next motorist to come along and ask for their ticket. If it is still valid for the time of the ticket issued wait until you get the penalty notice then send a copy of the NEW ticket and say the attendant must have mistakenly not noticed your ticket. You'll get off every time.