The Farm Cafe on the A17 at Fleet was blitzed at the weekend by cash-swapping conmen who returned next day in a cheeky repeat attempt.
Complex owner Bill Payne is urging other traders in the area to beware and refuse to change money.
He said: “We won’t be caught like that again and we don’t want anyone else to suffer it.”
The three men stole around £300 after bamboozling staff in both the cafe and the complex’s fruit shop early on Friday evening by asking to change £200 into £10 notes.
They tried at the plant shop, too, but were given short shrift by Bill Payne’s daughter Claire who was serving there.
The men, who were smartly dressed and had British-Asian accents, drove off in a blue MG Rover and no one realised anything was wrong until the tills were cashed up and the loss of £150 from each came to light.
Next day the same car was identified after one of the men tried asking for change at the fruit shop and escaped in it when he was challenged.
This time staff took the car number and rang police, who confirmed it was the same car.
On Friday night CCTV images from the tills were examined at Holbeach’s JWK Electrical where the scam showed up quite clearly.
Cafe manager Annette Ingle said: “We were amazed that one of them actually came back the next day and tried the same scam, but that time we were ready for him.
“The staff in the fruit shop asked him to go and see Claire, who was on the forklift, and when she spoke to him he made off.
“Now we’ve got the CCTV pictures up by all the tills and won’t be giving change.”
A staff member who doesn’t want to be named said: “I was at the till when one of the men did the funny business - he looked and sounded Asian, they all did.
“Next day I was sent out to get the car number and the man in the car looked familiar though I can’t say for sure he was one of the ones from the day before.”
Police yesterday confirmed they will be examining the CCTV images which they have received as part of their investigations.