Sarah, not her real name, had £20,000 stolen in an investment fraud so sophisticated it was 17 months before she discovered it was a scam.
Lloyds bank initially told her there was a 13-month time limit on reporting scams so it would only refund her £1,000.
Within a day of BBC Radio 4's Money Box investigating it refunded her in full.
UK Finance, which speaks for banks, says only a small number of cases ever fall outside the deadline and victims can complain to the Financial Ombudsman Service.
It states, among other things, that victims of push payment scams should be reimbursed within five working days, up to a value of £85,000 but that banks and payment service providers must be told within 13 months of the date of the last payment being made.
It replaced a previous, voluntary scheme and was intended to standardise responses to fraud across the finance industry.
It has been described by some as a "game changer" for improving protection for fraud victims.
But Louise Baxter, head of the Scams Team at National Trading Standards says the 13-month rule needs reviewing, reforming or removing.
"It doesn't provide protection to all consumers from fraud and scams," she says.
She believes the time limit should start from the point when a person realises their money has actually been stolen rather than, as is the case now, from the point of the last payment.
"Investment fraud can go on for a really long time," she says.
"You could get to a point where you didn't know you were a victim for quite a considerable amount of time after you made the payment so it would provide those extra protections for those consumers as well. "
Sarah, who shared her story under the condition of anonymity, believed she was making an ethical investment in social housing and had checked the firm out before taking the £20,000 out of her pension in October 2024.
"I felt that I had done all the due diligence, I had checked with Companies House, I had checked with the Law Society, I checked all the TrustPilot reviews," she says.
But she didn't realise what had happened until March 2026 so was only able to alert her bank months after the 13-month deadline.
She says Lloyds told her a £1,000 payment, which was made before the new rules came into force, would be refunded.
But not a second payment of £19,000, made after the new rules came in.
"It really floored me," she says.
"I had no understanding of the 13-month rule before it came in because it's impossible to spot these things. So if it's impossible to spot them how is the general public supposed to spot that?"
When the BBC approached Lloyds it said: "Upon further investigation of [Sarah's] case, and taking into consideration the specific circumstances of her investment scam case, we've made the decision to further refund her the £19,000. "
"Investing can be a great way to make money, but only when investing with legitimate, trusted companies.
If you think you have been the victim of any scam, it's important to report to your bank immediately," they added.
Sarah told the BBC: "I'm over the moon.
I just can't believe that in just over 24 hours it's changed. I'd gone from losing what I thought was a big part of my retirement money to having it reimbursed