My neighbor damaged my lateral service (sewer)

[Steve Woods]

My Lateral Service sewer line has a leak somewhere between my house and the Main Sewer. The Lateral Service goes under my property and then continues under my neighbors property. They have been having some work done on their property and could have damaged the pipe and caused the leak. I am having to hire a company to find the leak. I have been told that even if the service was found to be damaged on their property, by them or their contractor, then it is still my responsibility to find and repair any damage to the service. What can I do?