Is it legal for a water company to leak a homeowners leak continue for 6+years just because the bill was getting paid?

My mom’s house has had a massive water leak between the house and the meter for 6+ years. The director of the water company came out years ago and said the water wasn’t going thru the sewer and refunded 3 months of sewage. Since that time, all of the water bills have had the sewage as if it’s going thru the sewer resulting in incredibly high bills. My mom lost her years long battle with cancer in October. Since then I have been paying the bill with little to no help from the water department. Since probate is not finished and I do not own the house, I have been unable to find anyone to help me fix it. The line itself needs replaced and moved to the side of the house. Is the water company negligent for letting the leak continue because the bill has been getting paid? I realize the leak was my mom’s responsibility to fix but by paying the $1000/month bill and battling cancer, she was unable to do so. I see it as taking advantage of an elderly, dying woman. Is this just a moral issue or is there some legal recourse? They water company is city-owned and not publicly regulated. Any help in this matter, would be greatly appreciated. Thank you!