I had a plumber come out to give me a quote on replacing a sewer pipe I knew was broken. After looking the tech called me and gave me a verbal quote. I asked him to send me a formal written quote. 3 days later the company sent another tech who did a camera scope and told me the pipe was broken (duh) and I now owed $400 for the scope. I said I never asked for it nor authorized it. He said tenant signed authorization. I asked my tenant and he said the guy tried to call me but was unsuccessful and so he told tenant I had authorized it. I have refused to pay it and now got letter from them giving me 10 days or they will file a lien. What can I do to quash this?