That is exactly the right place to call and good advice if this is your problem. However, you may not be responsible for maintaining the pipes all the way to the main line connection OR for maintaining them to your property line.
Houses currently built in our city are required to have a cleanout riser, which is usually situated at the back of the sidewalk or at the back of the curb, depending on the sidewalk plan. There’s a lateral pipe coming into the wye-tee joint of the riser from the house (and that pipe is the property owner’s problem) and there’s a lateral pipe coming out of the joint and going to the main line (and that pipe is the city’s problem). The riser, itself, is the owner’s problem.
So check to see if you have a cleanout. If you do, then there’s a chance that anything to the street side of it is maintained by the city, the county, or their outsource company, even if it’s in the ROW. The permit center or Department of Public Works should be able to tell you who has the responsibility for which pipe, although you may be referred to a municipal utility district or other agency.
In Stockton, the limit of city maintenance for a sewer lateral is shown on Standard Drawing 64 of the City’s Standard Specifications and Plans. I have no idea whether other cities and counties have a similar limit of maintenance nor do I know where it would be written down. This is very much an ‘it depends on the community’ thing.
Here’s hoping that you have a cleanout riser between you and the break, and that the local rules make it their problem.