I bought a home over a year and a half ago that was advertised as City Sewer but in fact has a Septic tank.?

The previous owner lived there for fifteen years and rented it out. I recently spoke to the neighbors who told me that they have been having problems with the septic tank for years and many people that had rented the home complained about it flooding, so the owner had to have known it was not city sewer. I found out that I was not on city sewer due to a back up that cost $6000. I have been getting quotes to hook up and will cost nearly $10,000. this includes breaking up patio and sidewalk and replacing it, which needs to happen in order to get the pipes to the road. I still have the MLS paperwork that states City Sewer. I contacted the real estate broker that sold us the house and am waiting on him now. What are the chances that they repay the cost of damage and pay to hook us up to city sewer?