Received what looks like a scam (mail phishing fraud) letter from Client Negotiations Department for an overdue bill I know I do not owe. The are asking for $10,000 of a $20,00 overdue bill. The address they use is  337 Garden Oaks Blvd. #56676, Houston, TX 77018. "Document Binding Co of Houston. This is the second letter I have received, the other was from a different address, phone number and had a different price.