People walk past a Capital One banking center in New York’s financial district in 2013. (Brendan McDermid/Reuters)

Capital One said Thursday that it had resolved an internal technology issue that left customers across the country with multiple charges for the same debit card transactions on their accounts.

The company was vague about the cause and the number of accounts affected, but a spokesperson said the problem was not due to an external cause, such as a hack.

“Customers are being notified when they sign in to their accounts or contact us that their balances should now be accurate,” Capital One spokesperson Amanda Landers said Thursday morning in an email.

“Accounts have been credited for any inaccurate postings related to this issue,” Landers said. “Customers can continue accessing their accounts and our services via our online banking, mobile app, branches and ATM, and contact us if they have any further concerns. ”

Landers said “the internal tech issue impacted branch bank checking accounts that had debit transactions made on a particular day, so it affected a portion of our customers and accounts. I don’t have an estimate of that impact that I can share.”

The company reported having more than 65 million accounts at the end of 2016.

Twitter was full of messages from angry customers complaining of multiple charges for the same transaction against their checking accounts.

“I was stuck right in the middle of this one, and it really ruined my morning yesterday,” said Capital One customer Mitch Katz in an interview with The Post. “It appeared as if my card info had been stolen, and someone had taken $40 out of an ATM with it early Wednesday morning. It took forever to get through to Capital One. It was very frustrating. They should have known they were putting false withdrawal information on there. These days with all of the hacking and personal information being stolen, my first thought was that someone was taking money out of my account without my authorization. My debit card has been hacked before.”

“I woke up this morning, the charge is gone from my account. It just went away. They never sent me an email saying what happened,” Katz said. “From now on, I am going to check my account more than once every day.”

Others had similar stories.

“I had a negative $50 in my account and I thought I had at least $1,000 in there,”  Dean Robinson, who lives on Capitol Hill in Washington, D.C., said on Wednesday.

Robinson, 49, who works in technology, said he spent 50 minutes on hold before a Capital One employee immediately put money into the debit account and said the mix-up would be straightened out by the end of Wednesday.

As of Thursday morning, Robinson said, “it does appear that everything has been returned to my account. When I first saw it, I thought  I had made some terrible mistake. That I had not properly accounted for something. I was a bit distraught when I saw that negative balance. I have my rent to pay and the car payment to make. I was just hoping this wasn’t something I forgot.”

McLean, Va.-based Capital One Financial Group has 49,900 employees and was founded in 1994. The Fortune 100 firm had $350 billion in assets, $240 billion in deposits and revenue of $25.5 billion as of its 2016 fiscal year.