My daughter contracted to have her kitchen repaired after a water leak. The contractor gave her a lump sum estimate for the entire project. Which they agreed upon. During the project my daughter did some work and purchased some materials on her own to help reduce the cost. The contractor is demanding the full amount of the original contract. My daughter has asked for a itemized billing. He says he doesn’t have one. She has received a letter from the contractors attorney demanding for payment. Threatening a mechanics lien. What should she do?