Years ago, I came out of the house one morning to see a whole section of side yard that had sunk several feet to the point where it actually pulled apart a chain link fence. Thinking it must be a sink hole I called the county who dutifully dispatched an expert to come take a look. The good news was it wasn't a sink hole; the bad news was it a "trash pit" - i.e. the contractor had buried trash on the lot during construction about ten or so years earlier (long before Mrs G. bought the house prior to our marriage). While it took quite a bit of research, I was able to figure out who the builder was (not the builder of record who subbed the job out) and discovered - fortunately - he was still in the building business. I was able to get a hold of the owner who was pretty disinterested in my problem and dubious of his responsibility. He thought he ended the conversation by telling me he didn't see it as his problem, but I was welcome to sue him. I told him that I didn't think it was worthy of a lawsuit, but asked if he could provide me the name of his insurer so I could file a claim. (Most insurers in that particular area of insurance will drop a client if they don't identify their insurer when asked.) After a moment of dead silence, he asked me to repeat what I said. Clearly, now I had his interest. He asked me a few questions about what the county guy had said and asked if he could come over and take a look the next day. "That'd be great," I replied.
So he shows up the next morning, walks around a bit, and confirms what county guy said (duh). He then says, "How about this; I'll dig up the hole, fill it with concrete, top it with soil, level it out with the rest of the yard, lay down fresh sod, and fix the fence." "When?" "We can start next Monday and get it done in less than a day." "That'd be great," I replied. To his word, it looked good as new and we were transferred overseas a few months later. No idea how the repair held up over time.
Lesson: When dealing with a contractor/builder, if feasible, don't threaten a lawsuit; threaten filing a claim with their insurance.