Mass. customers say National Grid didn't tell them about electronic bill switch

WALTHAM, Mass. —

National Grid is under fire again from Massachusetts customers over billing problems.

Numerous gas and electric customers said the utility giant left them in the dark for months about a move from paper to electronic bills. Several said they only learned of the switch when a disconnection notice arrived in their mailbox in the last few weeks with a demand for hundreds of thousands of dollars.

Now, state regulators said some of those customers may be owed money back from the company.

This problem comes just weeks after National Grid failed to bill thousands of gas customers for the better part of the winter.

In March, state regulators called National Grid's billing problems "systemic" and "inexcusable."

Albert Mercado wasn't surprised last month to see an envelope from