A British Airways passenger was refused a refund for a cancelled flight even after she sent screenshots of the airline's website showing the option of a voucher was not mentioned.
Lesley Anderson says a voucher was issued "automatically" after she selected "Cancel and refund flight".
She is the latest person to accuse the airline of misleading its customers.
British Airways has said there is "no way" that vouchers can be issued without customers requesting them.
Ms Anderson, from Irvine in Ayrshire, had been due to fly from Glasgow to London to celebrate her birthday, but disruption caused by the coronavirus pandemic meant her flights were cancelled.
An email from BA included a link that took her to the "Manage my booking" section of its website, where she was presented with two main options: to rebook the cancelled flights "free of charge" or to get a "full refund" by cancelling the entire booking.
"I obviously chose the 'Cancel and refund flights' option," she says, "which then took me to the British Airways webpage that said, 'Thanks for completing your travel voucher application.' I was a bit gobsmacked."
"I definitely did not fill in any information about my name, my flights. I did not click submit, nothing like that at all. It just took me straight to that page and it issued me automatically with a voucher."
Even though Ms Anderson sent screenshots of the webpage showing that vouchers were not listed as an option and said she always wanted her money back, BA staff told her she had accepted vouchers and they could not be exchanged for cash.
Under EU law, when a flight is cancelled, passengers are entitled to their money back within seven days, although airlines can offer to rebook flights or issue vouchers for future travel, if that is what a customer prefers.
In Lesley's case, BA says that she filled in an application form and it is not possible for its online system to issue vouchers without that happening.
But numerous passengers have contacted Radio 4's consumer programme, You & Yours, with similar tales of receiving vouchers which they did not want.
The airline has said it will "always provide a refund if a customer is eligible".
"Since March, we have provided more than 2.1 million customers with cash refunds and more than 1.6 million with vouchers," BA said in a statement.
"Customers can request vouchers via our call centre, or by filling in details on an online vouchers form, and in each case, they are asked to confirm this before it is submitted."