Shoppers claimed to have travelled up to 100 miles after trusting Google’s listing for the new shop which claims it opened on May 1.
But the Swedish furniture giant had announced in March that the opening would be postponed until May 10.
The delay was blamed on the ‘Beast from the East’ blanketing the city in snow and forcing work to be abandoned for several days.
However, Google does not appear to have caught up with the announcement.
Would-be customers were turned away by workers who are busy preparing for the actual opening day, Devon Live reported.
One witness claimed “thousands” of flat-pack furniture fans in the South West had fallen for the wrong date.
Clair Louise Jones tweeted: "I am really disappointed such a massive firm cannot change its web page to reflect when your new Exeter store opens.
"Thousands have travelled too, but turned away without so much as a sorry."
Eleanor Hawkes said she "drove all the way to Exeter IKEA from Falmouth" expecting it to be open.
The Exeter store, which will be Ikea’s 21st in the UK, has been promoted through a series of events across Devon and Cornwall in the build-up to its opening.
Nick Earle, IKEA Exeter Store Manager, said: ““We understand that a small number of customers travelled to IKEA Exeter this weekend and we are really sorry for any inconvenience caused to these customers who we estimate was less than 50. The store may have seemed a lot busier due to an internal friends and family event taking place on Sunday, 6th May where there was also a planned routine fire drill.
"The store was originally due to open on 1st May. During the Beast from the East and extreme weather conditions in March, we halted construction to ensure the safety of the team. Since March, the revised opening date of Thursday 10th May has been widely communicated. We look forward to welcoming everyone when we open our doors on Thursday.”
