A train operator has said the cost of refunding rail season tickets amid the coronavirus lockdown is expected to total several million pounds.
More than a quarter of Greater Anglia's 60,000 season ticket holders have already submitted requests for refunds.
Coronavirus restrictions mean fewer staff are in offices able to process refunds, causing some delays.
"We are processing them ASAP but it is difficult because there is such a huge volume," a spokeswoman said.
Since government restrictions were introduced the company has faced a huge influx in requests for refunds.
A spokeswoman said: "We have had, in the last three weeks, 15,000 season ticket refund requests, that's eight times as many as normal."
"We expect to give out several million pounds in refunds."
A 28-day window is normally given for refunds but this has been extended to 56 days by the Department of Transport to allow rail companies to process the influx of requests.
The refunds are a mix of mainly annual, monthly and weekly season tickets which vary in price.
Ian Cannons is one of over 15,000 people to cancel their season ticket and says he is due more than £2,500.
"I applied for a refund back on 23 March when the timetable came out, it just wasn't practical to be going out," he said.
Mr Cannons said the original 28-day refund window was "reasonable" but he doesn't understand why the process of refunding rail customers takes longer than normal retail refunds.
Greater Anglia said it can take longer to refund some customers due to strict financial controls and checks that are necessary when processing large sums of money.
The company has also said it is facing additional challenges due to restrictions including: limited courier pick-ups for tickets handed in at stations; a call centre being closed or having staff work from home.
Only one office can process refunds of more than £500 and the company said it had redeployed more staff there while still limiting numbers to implement social distancing.