Couple's fury after getting £60 fine for parking at Carphone Warehouse in Milton Keynes

But that's exactly what happened when Ceri and Wayne Davies used the Elder Gate car park at Carphone Warehouse.

And they're warning other shoppers not to get caught out.

Mrs Davies said: "We parked outside the store as my husband needed to buy a new phone. We were in there for about a hour."

So it came as quite the shock when weeks later, they received a £60 fine for not registering their car.

"I thought it was a mistake," said the 58 year old.

"I wouldn't mind but I've been at that store three or four times before."

She returned to Carphone Warehouse which contacted parking firm UKPC, as well as making her own appeal. But it fell on deaf ears and UKPC upheld its initial fine.

"I feel it's really wrong - after all the business we have given Carphone Warehouse. My husband is furious.

"We are completely innocent and we were unaware. Someone in Carphone Warehouse should have told us. We didn't know to register our car."

But, it would seem, the store is aware of the problem and is trying to give customers a guiding hand.

The store manager told MK Citizen the system was brought in to stop commuters parking there and using the train station.

He said for the most part, the system works but conceded some customers have clearly missed the signs.

"There will be another sign on order and we've got A4 signs coming for the tills," he said.

However, Mrs Davies wasn't the only one to get caught out as many customers have taken to the web to complain.

One customer said: "I used this store to upgrade a phone, and despite putting my car registration number into the store's car parking system, I have now received a parking ticket. I have had to appeal this with the parking company. This is really not acceptable."

Another said: "Was in the store looking for a new phone and comparing contract prices. Two weeks later I received a £60 parking charge notice. Well done Carphone Warehouse, you've now lost four long-time customers."

And a third said: "Avoid at all costs. You will get a parking ticket. I parked here and popped into the store to look at a phone. A week later I received a parking ticket for £60. No member of staff told me to enter my car registration on to an iPad. The signs do not tell me to enter my car number plate. Disgraceful."