Many frustrated Comcast customers were slammed with service disruptions twice this week, with the telecom company pledging to issue credits to people left without service — but only if they call in.

A video outage Monday morning cut out some cable networks for Comcast customers, the company said. Most customers had no issues with Internet and phone service.

“We did not live up to expectations around 100 percent reliability with your TV service,” said Comcast spokesman Kevin McElearney. “Just reach out to us, and let us know you were impacted, and we’ll credit you, no questions asked.”

Comcast said the problem was related­ to an error in a network device­ that supports Comcast’s live video network. It rerouted channels, causing the service problems.

The wave of service problems flooded Comcast’s call centers result­ing in long wait times to speak with a company rep.

“We know exactly what went wrong and have fixed the issue and put in place technical measures to make sure that this doesn’t happen again,” McElearney said.

But yesterday, unrelated service issues­ resurfaced in Massachusetts and New Hampshire — sending Comcast customers back to the Web and social media to complain about television outages and Internet problems.

“Some of our New England-area customers experienced service inter­ruptions,” said Comcast spokesman Marc Goodman. “Our teams worked as quickly as possible to restore­ ser­vices, but we know we let our customers down by not pro­viding the reliability we promise and they have every right to expect, and we’re sorry for that.”

Comcast said yesterday’s interruption was caused by issues with maintenance work and was not connected to the problems Monday.

All service was restored by yesterday, Goodman said.