Car park chiefs have denied their technology is faulty after threatening a driver with court action.
Christine MacLeod received a summons to cough up £100 following a short stay in Ayr's Boswell Park site.
The stunned pensioner – who followed rules on the day and had bank statements to prove her transaction – has since refused to pay the fine.
It follows our story last year that motorists were being hit with dodgy fines despite paying up to park.
Bosses at Workflow Dynamics, who own the site next to the Gaiety Theatre, were forced to admit that an "unforseen IT issue" had led to fines being handed out "in error".
Alex MacLeod, 73, told Ayrshire Live: "My wife followed every instruction and paid to park. She uses the car park every two or three weeks so is no stranger to the system.
"Then we receive a letter which is very threatening in tone which demands payment of £100.
"It states that if you do not pay up, it will be passed to debt collectors and then on to the courts.
"That is very intimidating language and many people will feel the need just to pay up, regardless of whether they have done no wrong.
"My wife felt she should just pay up to avoid the hassle but we're not prepared to let it lie.
"We tried contacting the company on a number of occasions but got no response, they clearly just want the money."
When contacted by Ayrshire Live, bosses at Workflow Dynamics agreed to rescind the penalty charge notice (PCN).
A spokesman insisted the incident had been "an instance of user error" with one digit of a number plate entered incorrectly.
The spokesman added: "We can’t trace an appeal having been logged with us. But on the basis of the information provided we will cancel the PCN.
"This is standard practice in any instance where the user has a single character keying error."
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