HomeServe Problem of sewage waste in our yard--denial of service listed in exterior sewer line service agreement Norwalk, CT Nationwide

We had sewer line back-up into our house. We paid to have it examined and line cleared. The camera showed blockage and multiple breaks in the sewer line.

We have had HomeServe exterior sewer/septic line service agreement for over a year. In the Terms and Conditions document for exterior sewer/septic it states: "We will arrange and pay for the repair or replacement of a leaking or permanently blocked Exterior Sewer Service Line ..supporting a Residential Property, for which You have sole responsibility." 

Per the agreement, we called HomeServe to tell that we had a leaking line. The agreement says" Every part of your covered repair is taken care of for you--from finding a qualified technician to coordinating repairs.  All you have to do is call the 24-hour Repair Hotline number. It's that simple."

They sent a technician from another company who confirmed that there was a break in the line. (Both my husband and I saw the companies' video and saw the breaks.) He did not go past the first break as he was worried his camera was going to get caught in the hole. He confirmed that waste from our house would leak from that hole.

My husband called HomeServe while the Apollo Plumbing tech was here and put the tech on the line. HomeServe person heard for herself that the pipe leaked and had a break.

My husband has spent hours on the phone having each HS person he has talked to tell him that they would not cover the problem. Evidently, the next time we get sewage backing up into our house, they might pay for it however.

Why does HS not abide by the serivce agreement "arrange and pay for the repair or replacement of a leaking or permanently blocked Exterior Sewer Service Line" when we have documentation from two different companies of the leaking line??