Fed-up House of Fraser customers fear they will end up out of pocket as the company has gone silent about replacing the retailer's gift cards.
When it was bought by Sports Direct, concerned customers were told to send in gift cards for "a replacement".
But a month after the August deal, they have heard nothing and the chain is not responding to questions.
Angry Cathy Martin told the BBC: "They've stolen £150 from me - and thousands of others."
If the new owners fail to replace the cards, those who still had them when the department store chain went into administration will join a long queue of other creditors - meaning there will be little chance of getting their money back.
Sports Direct last week took a hard line on shoppers who ordered goods online but were not delivered before the chain was bought last month. They have been told not to expect a refund.
The company's PR advisers have failed to respond to emails and phone calls from the BBC, leading to growing fears that they may take an equally hard line with gift cards or vouchers bought before the collapse of the chain in August.
Adam French, consumer rights editor at Which? said: "This is appalling. It's worrying that the House of Fraser has gone silent on this."
'I feel like helping myself to £150 worth of stock!'
Cathy Martin ended up with a House of Fraser gift card in lieu of a refund last year and had not got round to using it by this summer.
"I took it to the Belfast store just after the announcement was made that the Chinese sale had failed and was told the gift cards were no longer being accepted," she said.
She sent the card to an address provided by the store, but has heard nothing since.
"I honestly feel like going and lifting £150 worth of stock and walking out! I mean, it's the same thing, isn't it?; except I'd be arrested and House of Fraser gets away with pretty much the same thing. They've stolen £150 from me - and thousands of others."
Are the gift cards worthless?
The gift card market has doubled in the past five years and is now estimated to be worth more than £6bn annually.
But many people may have discovered that the card that friends and family have bought them for Christmas or a birthday are now worthless.
That's because more retailers are going out of business, leaving gift card holders as creditors, which looks likely to happen to House of Fraser customers.
"When House of Fraser told people to send in their gift cards, we recommended they photocopy them and send them recorded delivery, with proof of postage, so they have some evidence," said Mr French of Which?
"Without that evidence they may have difficulty making a claim to the administrator."
Making a claim
You need to make a claim in writing to the administrator with proof of your vouchers or gift cards.
Administrators EY said : "Customers can submit a claim against the HF Stores Realisations Limited (formerly House of Fraser (Stores) Limited). However, this will be treated as an unsecured creditor claim and unfortunately they will only receive a very modest recovery against the amount claimed."
Another route is to claim to a credit card provider, such as your bank, if the gift cards were bought using plastic.
Section 75 of the Consumer Credit Act can make credit card providers jointly liable for breaches of contract with a trader when people buy on a credit card.
To have a chance of a claim, gift cards need to be worth more than £100 and bought on a credit card.
But with gift cards often bought by other people, it will mean contacting the giver to get them to chase the cash.