Work crew damage to an underground sewer pipe

For the past few weeks Comcast has been in my neighborhood running new cables underground. Last week they were working intensely in front of my house and in my front yard, side yard and drive way. At the same time I got what I thought at the time was a clog in the main sewer line. I got a plumber out here on Monday to take care of it but he found a problem. When he attempted to augur out the line he ran into what he called a trouble spot. He ran a camera down the drain and there's a solid obstruction now he couldn't push the camera further. He measured how far out the camera got and it was in the area they were running cables and marked it on the ground. He asked me if I had any utility crews working out here which I told him yes and was obvious due to the entire section of the property is heavily marked, he said they probably damaged the pipe. What can we do about this?