Cindy Meserve stood in front of the Maine Public Utilities Commission on Monday night with 15 pages of electric bills in hand, some as high as $4,395 for a single month’s worth of service, that CMP can’t explain despite months of complaints, phone calls and emails.

The problem came to light when CMP tried to deduct a $2,000 bill from her checking account as part of a monthly automatic payment program. The utility’s attempted withdrawal sent her account into overdraft, prompting a call from the bank. For decades, her monthly bill stayed steady at $187 a month.

“I am extremely frustrated to say the least,” the Buxton woman said. “I’m out thousands of dollars. I’m at my wit’s end. There is no accountability. You need to hold CMP to their promise to treat their customers fairly and adequately.”

Meserve was one of about 50 ratepayers to attend a PUC hearing in Hallowell on Monday to solicit public comment on CMP’s proposed rate hike. Central Maine Power wants an increase in electricity distribution rates of about $46.5 million, or 10.65 percent, for residential customers.

Many at Monday’s hearing asked the PUC to delay the rate hike, but some went farther, asking regulators to consider levying fines against CMP and forcing them to repay customers who had spent money seeking resolution to their rising energy bills by buying new appliances or checking wiring at CMP’s urging.

The company is seeking the rate hike because of increasing operating costs and to improve the reliability of its distribution system. Many at Monday’s hearing said the utility hasn’t earned the rate increase, with at least some who testified urging the commission to cut rates.

The PUC is investigating the utility’s switchover to a new billing system in 2017 that led to about 97,000 customers complaining that they had received bills that were at least 50 percent higher than bills received the year before. The PUC also is looking at how CMP’s customer service staff handled billing complaints and questions.

Last month, a Maine Sunday Telegram investigation found CMP mismanaged the rollout of its new billing system and customer complaints and misled the public about the scope of the problems.

The PUC staff has recommended that the commission cut about $30 million from the requested rate increase, including a reduction of CMP’s annual earnings of about $4 million to $6 million to stay in place until the utility meets certain customer service standards.