A Labour MP has told Sky News she had her bank account targeted by scammers three times in three weeks.
Carolyn Harris, who represents Swansea East and is deputy leader of Welsh Labour, said she went through four debit cards in a month after the raft of fraudulent transactions.
And she is worried more vulnerable customers will not know when cash is being taken from their accounts, or have access to their money when their cards are cancelled, if they don't use mobile banking apps.
The saga began on a Thursday in September when Ms Harris started receiving texts asking her to authorise payments, ranging from £300 to £1,500, which she continually declined.
"I phoned the bank that night and told them I thought someone was trying to scam me," she said. "I waited quite a long time to speak to the fraud team, then I got cut off."
Two days later when shopping in Swansea, the MP was alerted to a problem with her account again.
"I bought one thing with my card and it was fine, but when I went to the market to buy fruit and meat, my card got declined," she said.
"So I went to the cash point to get money out and it got declined again."
Ms Harris headed inside the bank to get advice, but after a long queue, she was told any queries had to go through the fraud team - meaning another 40 minute wait on the phone to speak to the department.
"The person wasn't very nice if I am honest and only wanted one word answers," she said.
"After a quite fraught conversation, they said I had been scammed, they cancelled my card and promised another would be delivered five days later, which it was."
But the Labour politician was soon hit again by another scammer.
'I was stuck in London without any money'
"I'd had my new card for three days and was sat in my flat in London on a Sunday night before heading into parliament the next morning," said Ms Harris.
"I took a look at my account to see if money that had been taken before had been refunded and I saw more transactions.
"I was worried, I was stuck in London without any money as I only had my card, so couldn't get anything."
Another phone call and another cancelled card later, she was thankfully able to download her new card onto her phone so she could use it straight away, while the physical version would be sent to her home by the end of the week.
But her scamming experience wasn't over yet.
"Roll on another two weeks and I am lying on a sun lounger on holiday in Portugal," she said. "And there are even more transactions, this time all going to either Facebook or in foreign currencies."
Back on the phone to the bank and it appeared the scammers had managed to set up standing orders from her account, meaning she wasn't even notified of the amounts going out.
"That's three weeks, three lots of scams, and four cards in a month," she said. "And [the bank] had no idea at all how it happened, no-one seems to know."
Ms Harris told the Home Affairs Committee that she called the police on her return to the UK, as not only had scammers targeted her, but they'd also targeted one of her staff members, which she thought was suspicious.
"They came to see me, but they can't do anything at all," she said. "Don't get me wrong, my local force are brilliant, but all these transactions were happening abroad and they aren't able to sort this."
For Ms Harris, it was a case of inconvenience, needing to get the new cards and update details for her subscriptions, like Netflix, Amazon and her car tax.
But she is concerned that not everyone would be in the same position.
"I had an app on my phone so I could check transactions and I was able to download a new card onto my phone too," she said. "There is no way on God's earth some pensioners would be able to do that.
"Even my husband doesn't have an app on his phone and doesn't check... and he doesn't think that is abnormal.
"If it happened to my mother, she wouldn't know until the bank statement came the next month or until her card got declined.
"And when I was on holiday, I asked if I could go into a branch with a passport and get money out and they said no. What would she have done?"
'There has to be a better way'
The Labour MP said it made her worry even more about local high street branches closing down, adding: "Technology is a wonderful thing, but only if you are up to date with it."
She said "there has to be a better way" for banks to stop fraud happening in the first place and making their customers aware if they aren't online or using mobile banking.
"I remember booking three flights once and when I went online to book another two... my card got declined and I got a phone call, so the technology is there," she said.
"Banks have to get better at telling people."
Action Fraud has published advice on how to protect yourself and your account:
• Don't throw out anything with your name, address or financial details without shredding it first
• Don't leave things like bills lying around for others to look at
• Never reveal your full password, login details or account numbers to anyone who contacts you through an unsolicited call or email
• Ask any caller to give you a main switchboard number, or hang up and call your bank back on the legitimate phone number printed on your bank statements
• Check your statements carefully and reporting anything suspicious to the financial institution concerned.