Holidaymakers have said travel firms are hiking prices for customers trying to rebook trips put off by the coronavirus pandemic.
Travellers have also said they are unhappy at being offered vouchers instead of refunds by firms after trips were cancelled.
Worse, when they come to re-book, people have found the credit notes issued can fall as much as 40% short of the price now needed for the holiday, Money Mail reports.
One couple told the paper they would have to pay £114 more to take the exact same trip in October after their April honeymoon plans were called off.
Airlines say "dynamic pricing" - where costs adjust automatically according to demand - is behind many shifts, but some passengers say the fare for rebooking is more than a new ticket on the same flight.
One was told rebooking a flight would cost him £122, when the airline was selling a new seat on the same plane for £44.
Dave and Linda Briggs from Clitheroe, Lancs, told the paper they were asked to pay 24% more to rebook a cottage in Northumberland for the same week next year.
Dave, 74, said: "I feel the company is taking advantage of this situation. It's not fair that we should have to pay more for the same holiday."
Martyn James, from consumer complaints service Resolver, said: "I understand there could be seasonal variations, but if you can book at the same time there is no reason why that should be more expensive."
Customers are also frequently being offered vouchers rather than their money back - meaning they will then have to re-book with the same firm.
That's despite the fact you are legally entitled to the money.
Writing in his weekly newsletter, Martin Lewis explained: "Under EU reg 261/2004 (still in force until Dec), if your flight is cancelled you legally must get a choice between a full refund or an alternative flight. So of course right now that means refunds.
"While the law is plain, some are making you jump through hoops, because the airline industry is on its last legs. So do give some consideration to accepting a voucher.
"But if you want to get cash and it's not offering it, usually the easy route is to call, though expect a long wait. An alternative would be to try using chargeback on your credit or debit card to get your money back."
Resolver's James said the key to boosting your chances of getting a refund or a good deal was staying calm.
"The key to dealing with any crisis is empathy," he said.
"You'll get more if you acknowledge that there's a person on the other end of the line who, like you, is having a really bad day.
"Firms are facing an onslaught and are terrified of going out of business. We've heard reports of people being cajoled, or on occasion manipulated, into cancelling or accepting things they don't want.
"So before you negotiate, ask yourself: Is this urgent? If you do it now you'll get a Blitz mentality from customer services."
He added that people should think about what they're willing to accept from the firm.
"If you want to get a good result, make a point of saying how you would like to help it stay in business," James said.
"Don't feel under pressure to immediately rebook a flight. If anyone gives you a deadline, tell them exactly how much time you need.
"If we all have a cup of tea, calm down and walk away from the computer for a little bit, you should get a better deal. When the dust settles, there might be bargains to be had."