Probably crappy. I got one too, but I had to replace my sewer line shortly after I bought the house (water lines are still fine with plenty of pressure) so I don't need any damn insurance on that. There are all sorts of folks preying on the elderly these days (just like they did on minorities since the Civil War - which really was not very civil). Really shitty stuff.
Back in the old days the sewer lines were made of tar paper or before that cast iron and they would either rust out or tree roots would eventually grow through them and clog them. I've lived here all my life and can't think of a single time the incoming water lines have ever had to be replaced.
Call up the BBB and ask or report it. Call a TV station or radio station with reporters who do consumer protection and talk to them if it gripes you that much (probably after you call and talk to them first). Go get 'em tiger.