MANILA (3RD UPDATE) - Bank of the Philippine Islands President Cezar Consing on Wednesday apologized to their customers who were affected by a "system glitch," resulting in thousands of pesos being debited from their accounts.

"I apologize very earnestly and very sincerely to our clients who had been adversely affected by this," he said in an interview with ANC's Market Edge with Cathy Yang.

Consing explained that the unauthorized transactions were not caused by hacking but a system glitch.

"This is a data processing glitch. I have to emphasize: this is not a hack at all. This is an internal issue, and so what we have to do is we had to take our systems down this morning," he said.

He said their system "picked up the wrong file" when it ran a batch process Tuesday night, running instead the file for transactions dated April 27 to May 2.

Clients who transacted with the bank on those dates may have had their transactions reported twice, hence the double credit or debit.

Consing assured clients that the corrections would be made within the day.

"So over the next few hours, we are working on making sure that the double debits are corrected and the double credits are corrected. Within the day, the right amounts will appear," he said.

"We will make sure that no one--I repeat, no one--has lost money," he added.

Incoming Bangko Sentral Governor Nestor Espenilla described the situation as "unfortunate."

"Seemingly losing money like that is definitely upsetting...We should allow BPI to resolve its internal problem," he told ANC.

While he said operational issues such as what happened in BPI are "isolated cases" and are "peculiar to a particular institution," Espenilla said the BSP will later investigate the situation independently.

"In a situation like this, the BSP just lets first the bank to fix the problem, and there's time enough to look deeper into the issue," he said.

Customers of the bank on Wednesday morning reported unauthorized withdrawals and deposits, reaching thousands of pesos, from their accounts.

"What we can be certain about is that we will make every effort that this will not happen again. What you can also be certain about is that we will make sure no one loses money on account of this system glitch," Consing said.