They were booked with Bluebridge cross from Picton to Wellington on Tuesday, after their earlier booking with Interislander was cancelled.
The Interislander's Kaitaki has been out of action for a month due to a gearbox issue and Bluebridge has cancelled sailings aboard the stricken Feronia ferry for the third day in a row after an engineering fault was discovered on Sunday night.
Chris Banney and Jenny Cassells planned to spend four weeks in the South Island and two weeks in the North, before flying home to Mackay in Queensland.
Banney said the trip was extra special because Cassells has motor neurone disease and the couple are not sure how long she has left.
They were notified on March 20 that their ferry crossing with Interislander from Picton to Wellington on March 28 was cancelled when the Kaitaki was taken out of service.
"We were on the line ringing them after that for four hours. We just gave up, there was no answer."
Banney said their travel agent was later able to get them a booking on the Bluebridge for April 4, but it meant an extra week in the top of the South Island.
Several hours before that sailing - got a text to say it had been cancelled with no option to rebook before April 23.
Banney said he was shocked with the lack of customer service from both companies and the cancellations and lack of communication had put a dampener on their holiday. He has yet to receive a refund for either booking.
The couple have rebooked their flights home and will return their campervan nine days early - they expect to lose around $4000.
"We can get on a plane and rehire another motor home over there, but why should we? We've had enough."
Banney said the ferry disruptions were a hot topic around the country and he had heard stories of people sleeping on concrete and the ferry terminals, waiting to be the first to show up in the hope of getting a booking.
He said while the couple had a great time in the South Island, he did not think they would ever return.
Police were called to the Bluebridge terminal in Picton yesterday after two sailings were cancelled, resulting in some "loud and upset" passengers. A spokesperson said there were no specific instances of abuse or bad behaviour.
It came after a call to police on March 26 after reports of an angry passenger yelling at staff.
Accommodation providers in Picton are also dealing with frustrated people struggling to find accommodation or change their plans due to ongoing ferry disruptions.
Piwaka Lodge and Backpackers owner Nicci Fitzgerald said her ethos was not to turn anyone away so she had been finding space wherever she could - on couches or in storerooms in some cases.
The ferry woes had been ongoing for the past three months and were made more difficult by people being told different things when it came to cancellations and bookings, she said.
She said it was Murphy's Law that things were going wrong for Bluebridge and the Interislander at the same time, after the ships had been serviced.
"A ferry is not something that you can just walk down to a caryard and buy, so these [new ferries] are going to be completely built to spec and I think we're going to have a world class fleet, but in the meantime, it's just struggling through."
Aldan Lodge Motel supervisor Melissa Huntley said it had been a hectic few months with cancellations.
"We're fully booked and then we get abused and it's not our fault, we are trying to do the best we can but we are just getting sick of it, it's just constant, every day there is something.
"You know, people just want to get home or they've got something they've got to get to, I feel sorry for them."
Huntley said she was telling people to consider flying across Cook Strait instead of booking a ferry.
"In the future book a plane, it's not worth the risk."