David, 42, who was meeting a friend for a coffee at the Marina, says he was twice only able to enter the first part of his registration before he managed to still pay for and get a £1.50p ticket.
He added: "I left within my allocated time and then I got a letter.”
The letter, which stated he owed a £100 parking charge – to be reduced to £60 if paid within 14 days – left David surprised.
"I only entered part of the registration but I thought they wouldn’t give me a ticket if there was anything wrong,” he said.
"There’s other car parks I’ve used where you put the registration, the first three letters, and then it picks up your car.
"I just thought it was one of those ones.”
Northwest Parking Management, which runs the car park, said it is unable to comment on a specific parking charge notice (PCN).
It added its tariffs and terms and conditions are “clearly displayed” throughout the site with signs stating that “Drivers must enter the full and correct vehicle registration into the payment machine”.
The company said: “When a motorist fails to enter their full and correct vehicle registration number into the payment machine a PCN is issued and this is classed as a keying error.
"As per the British Parking Association Code of Practice Section 17.4B Major Keying Errors, this states that one of the instances classed as a major keying error is ‘Motorist made multiple keying errors (beyond one character being entered incorrectly).
“If this motorist submitted an appeal and it has been declined then they must have entered multiple digits incorrectly.”
David said the company acknowledged during an appeal that it had received an initial payment and reduced his fine to £20.
He still to pay, however, in a dispute which dates back to last October, and said the sum he now owes has shot back up to £170.
David, who does not plan to return to the car park, said: "I didn’t overstay what I thought I was allocated.
"I paid, I didn’t do anything wrong.”