Motorists have contacted the Melton Times to complain they have been fined for parking after mistakenly typing in the wrong car registration number on their ticket.
They all say they paid to leave their vehicles in the Bell Centre car park in Melton and are being punished for making a small error.
Smart Parking issued initial fines to them of £60, but those have now escalated to more than £100 when drivers challenged them.
Shirley Gray (79), of Asfordby, mistakenly put a nought instead of a zero when asked to give her registration number.
Her fine is now £160 and she has refused to pay, despite being fearful of the consequences after being chased by a debt collections agency.
She said: “It’s a bit worrying now.
“I’m wondering if they will come and take my car away, but my family has told me I shouldn’t pay it.”
Mrs Gray added: “The number zero and the letter O look exactly the same on the machine.
“Anyone could make this mistake. It’s a lot of money for a pensioner to find.”
Mick Cole, of Rearsby, is querying a fine of £100 after making a similar mistake when buying his ticket in the same car park.
He inputted a Y instead of a V for his car number plate when buying his ticket.
The 73-year-old said: “It’s a bit draconian, this.
“Fining someone £100 for getting a number wrong on a ticket is really unfair.
“The Y and the V look the same on the machine.”
Rachel Bayswater, of Melton, put an O and an E in the wrong sequence on her ticket.
She said the machine was in a dark location so it was difficult to see clearly.
“I am flabbergasted and extremely annoyed”, said Rachel.
A spokesman for Smart Parking said: “At the Bell Centre, there are numerous signs across the site which clearly highlight the terms and condition of use.
“Included in these terms, is the condition that motorists must enter their full, correct vehicle registration when using the payment machine at the car park.
“In regard to the three cases highlighted, none of them did this and so correctly received charges.”