AUGUSTA — Summit Natural Gas of Maine paid more than $100,000 in reimbursements to customers in the Kennebec valley after missing nearly 400 deadlines for service.

The affected customers were told in June that they would have natural gas service by Nov. 1, according to a document that the company filed Friday with the Maine Public Utilities Commission, the state’s energy regulator. When those customers didn’t have service by mid-December, it triggered payments required under a company plan approved by the commission in 2013, when the utility began building a massive network from Richmond to Madison.

Most of the 389 affected customers are residential users, said Stacey Fitts, Summit’s director of governmental and regulatory affairs, but some commercial users also received payments, which totaled $111,200. The average payment was $285, with the company paying $50 for each week of missed service per meter up to a capped total of $250. Some customers had more than one meter.

Fitts said the company had an ambitious plan to sign customers up in its early stages and missed deadlines for a variety of reasons, including weather.

Reimbursed customers are widely scattered across the region, he said, but Gardiner is particularly affected. He said some of the customers waited only one or two weeks longer for service, while some remain unserved. He said the company is working to get gas to them.

“You won’t see those kinds of numbers over and over and over again,” Fitts said.

This is the first time that the utility has had to reimburse customers in this way, but Summit made headlines for a different reimbursement issue in November, when a contractor hired to do heating conversions for more than 100 Summit customers after being promoted by the utility suddenly closed without refunding deposits for their work.

That led to a period of angst, particularly in Yarmouth, Falmouth and Cumberland, where Summit has another pipeline network, before Summit elected to pay the customers back. People in those southern Maine towns weren’t affected by the rate plan reimbursement.