The passengers of Ryanair described the months of frustration and confusion due to the batted compensation checks.

The airline has apologised, saying that a “very small number” of cheques processed in July had been sent out without a signature due to an administrative error.

The consumer complaints service Resolver said it was aware that a number of Ryanair passengers had encountered problems with unsigned cheques issued when flights had been delayed or scrapped.

The airline cancelled up to 30 flights due to an Irish pilots’ strike last month, affecting 5,000 passengers. Another strike earlier this month by pilots in five European countries resulted in hundreds of flights being cancelled.

Ryanair said the cheques had been reissued to customers last week with a letter of explanation.

“We apologise again for any inconvenience caused to customers,” the airline told the BBC.

Paul Cooper said his group’s return flights home from Portugal had been cancelled eight hours before they were due to go on holiday. “It ruined the holiday, as it was a week of arranging to get home,” he said.

Ryanair refunded the cost of the return flights and an extra night’s accommodation within about two months. It also awarded compensation of £1,852.30 for the four cancelled flights.

“The cheque was sent out to me and cashed, but the day before it cleared in the bank they cancelled the cheque from their end,” |Cooper said.

With no customer services line to contact, Cooper said he had repeatedly sent emails to the airline trying to get the compensation, but each one took 28 days to be replied to. Eventually he was told to apply through Ryanair’s complaints tracker, but the system did not recognise his name or reference number.

When he asked Ryanair for further advice, he was directedto the same system, he said. “It’s just ridiculous, it’s been going on for nearly a year now. I’ve wasted so many hours of my life,” he said. “I would never fly with them again. I don’t care if they are the cheapest – they are a disgusting company.”

A number of other passengers have complained on social media of delays in receiving compensation because cheques had failed to clear.

“Ryanair, I have been trying to get hold of someone urgently as my bank are concerned because a compensation cheque that I received has bounced. I think that this is outrageous, the bank said the bank details provided do not exist … How is this possible with a printed cheque?” one customer wrote on Twitter.

Another wrote on Facebook: “Ryanair sent me a cheque for compensation then bounced the cheque … ended up costing me €32 (£29) for the privilege. Shame on you, Ryanair. Won’t respond to emails and operator just put the phone down on me.”

One passenger tweeted: “Ryanair, I would love to know why the cheque you sent me for compensation has bounced … Bank assure me this is your fault, wait 1 hour 20 on hold and your ‘customer services’ can’t help and there is no number to call to those who can? Please assure me of a call to fix this asap.”

They said they were still waiting for the money 11 days later: “Have contacted your call centre numerous times and just get a generic email saying my case is being delayed because I am obviously not the only person waiting for over a month for compensation.”

The airline told the BBC: “Ryanair complies fully with EU261 legislation, under which no compensation is payable to customers when the delay/cancellation is beyond the airline’s control.

“If these strikes, by a tiny minority of Ryanair pilots, were within Ryanair’s control, there would have been no strikes and no cancellations.”

Cooper said he had been left so desperate he was planning on taking direct action: “My next plan is to print out my correspondence, fly to Dublin and confront them. It’s a matter of principle now,” he said.