For most of last year, Central Maine Power didn’t bill MIPR Corp. for all of the electricity it used.

In March 2018, chief financial officer Courtney Lee discovered that the Newcastle industrial conveyor belt manufacturer had been getting billed for only two of its three accounts. Her books showed MIPR had been using but not paying for electricity supplied by that account since late fall.

Lee called CMP to report the billing error. A clerk insisted the third account had a zero balance. But in June a CMP meter reader walked into the office to demand payment. Lee was confused and asked for a paper bill.

In November, after nine months of calling, MIPR finally got a $1,500 past-due bill on the third account.

It was too much to pay all at once, so MIPR agreed to repay the past-due bill over time while it continued to pay all new charges in full. Lee assumed the billing problem was over, but she kept getting past-due notices, late fees and disconnect warnings despite timely payments.

“I called and said, ‘What the heck?’ and I got an ‘I’m sorry, I’ll take care of it,’ ” Lee said.

She kept careful records of every call, including the names of every CMP employee who spoke to her.

On March 11, despite months of assurances, CMP cut MIPR’s power on the third account. Without it, the manufacturer couldn’t run its equipment. Internet and toll-free phone lines went dark. Customers who wanted to buy gaskets couldn’t reach MIPR.

With documentation in hand, Lee called to complain. CMP quickly restored power and waived all fees, but she learned that none of the customer service representatives who talked to her between June 2018 and March 2019 had put so much as a single note in the company’s file.

In a March complaint to the Maine Public Utilities Commission, Lee wrote: “After many attempts to make sure our account was secure and not in any disconnect status, I feel CMP has not taken care of us the way we tried to take care of them by notifying them they hadn’t billed us!”