"It's been looking after itself, basically," Jennifer Adams told the Herald.
That was until June, when the Manukau couple realised they could no longer access their online banking.
Then, they received an email from Barclays saying they had insufficient funds to make a mortgage payment.
"We were shocked, because last time we checked there was around six thousand pounds in there, now completely gone."
Paul Adams called the bank, which said thousands of pounds had been withdrawn from the account both from a branch and from UK ATMs; thousands of kilometres from where the Adams' were living at the time.
"They assured us at the time 'don't worry this is obviously fraud, you'll get your money back' and we obviously trusted them," Jennifer Adams said.
"For months we were thinking they were sorting it out."
After weeks of calling the bank back and being told the account was "under review", the couple began to get frustrated.
"It got to the point where we thought 'this is ridiculous, how long can a review take?' "
Then, the bank closed their account on October 13 without the couple's knowledge.
Barclays said it had sent a letter, but it had sent it to the couple's former Tottenham address, which the Adams had put a stop-post note on in person years ago.
When Adams asked why Barclays had closed the account, they were told it was because they didn't fit the bank's criteria, but Barclays refused to elaborate on what that meant, she said.
They have since filed a complaint about the account's closure as well as the missing money.
Despite spending hours on the phone, no one was able to tell the couple what was happening with either.
"It's really stressful because you think your money's going to be safe in the bank. It really feels like we're not getting our money back."
Since being contacted by the Herald on Sunday, Barclays have contacted Paul Adams and confirmed it will be refunding the couple's stolen money and re-opening their account.
"When Mr and Mrs Adams left the UK in September 2011, as per their request, we ensured that no statements were sent to their UK address," a bank spokeswoman said.
"This was in place until June 2016, when an individual rang Barclays purporting to be Mr Adams and requesting for a new card and PIN be sent to their previous UK address.
"The individual was able to answer security questions that would only have been known by the customer. It is now evident that this was a targeted and sophisticated fraudster at work."