Under pressure from state and federal elected officials, Buffalo-based M&T Bank said it will compensate customers hurt by problems when it converted the systems of the former People’s United Bank over to its own.

M&T bought Bridgeport-based People’s United earlier this year.

During the conversion over Labor Day weekend, M&T accidentally locking some customers out of their accounts. Lines of frustrated depositors and borrowers were reported at local branches.

In a letter to U.S. Sens. Richard Blumenthal (D-CT), Patrick Leahy (D-VT), Elizabeth Warren (D-MA), Ed Markey (D-MA) and Bernie Sanders (I-VT), who had criticized the mistakes and pressured M&T to compensate its customers, M&T chairman and CEO René Jones said the bank apologized to those affected by the errors.

“Though the vast majority of customers integrated smoothly into our systems, we came up short for those who experienced issues,” he said. “We recognize that many customers had interruptions in their ability to view and transact with their accounts digitally or online.”

Through the end of October, Jones said, M&T would waive consumer checking and savings fees and is not assessing late fees for consumer and mortgage loan payments, with front-line staff authorized to waive other fees “as appropriate.”

The bank is also planning to “provide appropriate financial renumeration” for customers who couldn’t access their money due to the conversion and has begun to reimburse customers for any late fees the conversion problems caused.

Jones noted that complaints M&T received represented around 0.6 percent of the almost 1 million new customers with 1.7 million accounts the bank onboarded during the conversions.

In a joint statement released along with Jones’ letter, the five senators said they appreciated M&T’s actions.

“M&T Bank’s commitment to compensate customers who were adversely impacted by the conversion – whether missing payments or denied access to their money — is a welcome step toward making things right,” the statement said. “We are encouraged by M&T Bank’s prompt action in response to our letter, but will continue monitoring the situation to make sure M&T follows through with their promises. Consumers need swift relief and remedy now for the hardships and stress the conversion failures caused.”