Foundation Repair Warranty

[Marshall Hooper]

We remodeled a home and have been living in it. In Feb. 2016, we paid a foundation company $6000 to level the home. They put piers on the outside of the home, but not the inside and I noticed a slant in the middle of the home. I went back and forth with their VP of Sales about how I paid them to level the home, but they didn't do it, so after some disgruntled emails back and forth (i even tell him that I fear we will not be able to sell the home one day because of it), we finally agreed on $500 for them to come back out and put 2 more piers into the middle of the home. I told him I still didn't think it worked, but he said we had to wait for the home to settle before we knew anything. 

Fast forward to today and we list the home, get it under contract in 5 days, and then the buyers terminate the contract because the foundation. They said it's too high on the exterior and slants into the middle. Exactly what my concern was from 2 years before. 

The foundation company is now wanting to charge an additional $3500 to put in 4 more piers, not to mention I will have to spend another $4-$6k to repair and restain the hardwoods, which can't really be done while we are living there. 

My question is, should I not be under warranty for this? I paid them $6k and explicitly pointed out the issue of the low middle area of the home, and they did not fix the issue. We've had 2 hydrastatic tests done and both have come up excellent, so it's not a leak under the house. I feel that they should be offering to repair this work for free, especially knowing that I will have a huge cost to repair the hardwoods now. 

TIA