The Northern Ireland Consumer Council received almost five times as many complaints about airlines during the coronavirus crisis compared to the same period last year.
Most of the grievances concerned difficulties in obtaining refunds for cancelled flights.
The Consumer Council said the number of complaints and queries had surged from 131 between March 1 and May 13 in 2019 to 615 during the same period this year.
The data also showed that 475 out of 615 issues were about refunds for cancellations.
Richard Williams, the Consumer Council's head of transport policy, said the watchdog had forced airlines to return over £100,000 in refunds to consumers affected by cancelled flights.
DUP MP Gavin Robinson praised the organisation for its work and called on airlines to issue timely refunds.
"People are entitled to refunds and payment within 14 days," he said. "Airlines have a responsibility to make sure their customers aren't adversely affected by their inability to refund cancellations and if they're struggling they need to talk to Government."
Ulster Unionist MLA Andy Allen said it was time airlines "stepped up to the plate" with regard to issuing refunds.
"Airlines need to act responsibly and give hard-pressed consumers their money back," he said.
"A number of people have contacted my constituency office after being impacted by cancelled flights.
"It's important that airlines act responsibly to support their customers."
He added: "Covid-19 is no one's fault, and while I appreciate that airlines aren't to blame for the cancellations, they do need to give more support to their customers and improve the flow of information during these difficult times."
The revelation comes as Parliamentary Under Secretary of State at the Department for Transport Kelly Tolhurst and the Civil Aviation Authority (CAA) today face the Westminster Select Committee on Transport to explain the Government's policy on airline refunds.
Mr Williams confirmed that between March 1 and May 13 this year, the 615 contacts about airlines represented "a 369% increase compared to the same period last year", or 4.7 times more.
"Of these, 475 were in relation to difficulties in obtaining refunds for cancelled flights," he said. "In this period, the Consumer Council has managed to get airlines to return over £100,000 in refunds to consumers affected by cancelled flights."
Mr Williams said the pandemic has caused "an unprecedented crisis" for both the aviation industry and for airline passengers.
"Whilst airlines are facing an uncertain future, we are seeing large numbers of consumers worried about losing money as airlines struggle to fulfil their legal obligation to provide refunds," he said. "This recommends that vouchers should guarantee a cash refund if unused after 12 months or if the airline goes bust.
"We believe that with these guarantees, vouchers would be more attractive to many consumers and could ease the financial pressure on airlines; however, the bottom line of a cash refund must remain an option for those consumers that need it."
The Consumer Council is on Freephone 0800 121 6022 or email email@example.com