Laura Thomson and Sam Sciortino, from Woking, planned a Sunday ceremony in Santorini but will now marry on Monday.
The bride-to-be’s brother and family – including three bridesmaids – waited at Heathrow for 13 hours on Saturday before leaving without their luggage.
They have now booked flights with a different airline.
‘So let down’
Ms Thomson said: “We have had to contact suppliers, and change all the arrangements we had planned.”
“We’ve been planning our big day for two years only to be forced to rush around and change everything to take place a day later.”
The couple flew to Santorini earlier in the week, ahead of their guests. They said an aunt and uncle were also caught up in the BA disruption.
Ms Thomson said: “My brother is one of the groomsmen, and my nieces and sister-in-law are my bridesmaids, so naturally I wanted them to share the day with us.
“They booked with British Airways because they thought it was a reliable company.
“We feel so let down.”
Ms Thomson’s sister-in-law Marcia Thomson said: “We are devastated that this has happened.
“Our luggage had already been checked in and after waiting for 13 hours at the airport we were forced to leave without it.
“Luckily we have managed to get flights to Crete this evening with a different airline.
“We will have to get a ferry from there to Santorini on Monday morning just in time for the wedding, but without our bridesmaids dresses.”
Posting on Facebook Ms Thomson shared her disappointment with family and friends.
“I am just a shell of myself right now. We are absolutely shattered,” she said.
“I have been in tears with our dream of how it should have been slowly fading away, knowing I can’t share the day with my family the way I imagined.”
She added: “The hotel have been very accommodating but we’ve incurred extra costs as all the food has had to be paid for again.”
“We had a family cruise booked which also had to be cancelled and we have lost money on that as well.”
Mr Sciortino said: “It’s one of those things you don’t think will happen to you but we’ve been so lucky that we have managed to rearrange it even though there are certain things that we will be missing.”
By Rozina Sini, BBC’s UGC and Social News Team
Read more: http://www.bbc.co.uk/news/uk-40075555