The mistake meant the furious trippers had to spend an extra four hours on their coach as the red-faced driver headed from the town in the middle of Belgium (population 15,000) to the French city (population 220,000) they had first intended.
By the time the coach party from Gloucestershire arrived in France, they only had two hours to spend in the shops before they closed for the night.
After leaving Cheltenham, the driver of the coach ended up 100 miles off course in Lille, Belgium (ringed, right) when they should have arrived in Lille, France (ringed, centre)
"A few of us started to wonder what was going on when we saw signs for Eindhoven, which clearly isn't in France.
"But the driver wouldn't be told - he insisted he knew what he was doing.
"When it became glaringly obvious we were heading the wrong way there were some mixed emotions on board.
"A few people were laughing and joking about it - but others were pretty annoyed and they told the driver so.
"We ended up spending more than seven hours on the bus which is not my idea of a great day trip."
The trippers were all from the Cheltenham and Gloucester Sports and Social Club and had saved up during the year for the £150-a-head trip to Lille to do some Christmas shopping in the city which stands on the Deule River in northern France.
Past sat-nav blunders have seen lorry drivers being directed down roads unsuitable for large vehicles, leading to them becoming trapped.
Some passengers on the Lille-bound coach didn't to see the funny side of the situation and are now asking for their money back.
"We ended up only having two hours in the Lille shops so it was all a bit of a rush and a lot of us weren't able to buy as much as we wanted," added the passenger.
"The whole trip was blighted, really, because on the trip back to Ostend the next morning, following our night in a hotel, the driver switched off his sat-nav - but ended up on a road with a low bridge that he couldn't get under.
"He had to retrace his steps and find another road - which added another hour to the time we spent on the bus.
"We are all hoping after this debacle that we will have our money refunded because we didn't get what we paid for."
A spokesman for the C&G Sports and Social Club said: "We're very sorry that our staff and families have been disappointed in this instance, especially as we run so many successful coach trips throughout the course of the year.
"The committee will be meeting to look at ways to make this up to the staff involved."
The trippers were all from the Cheltenham and Gloucester Sports and Social Club and had saved up during the year for the £150-a-head trip