Contractors Lien Question

[Steve Corwin]

Had a sewer company snake out line at my rental home.  2 weeks later drains backed up again and had another company look at it.  They did a camera scope, told me pipe busted and gave me what I thought was an expensive quote.  Called first company back and asked them to come look at it again since they had supposedly fixed it the first time.  Spoke to tech on a Friday and he confirmed pipe busted and gave me an even more expensive verbal quote.  Asked him to send me a formal written quote.  Unbeknownst to me on Monday they sent out another tech who did a camera scope and called me with his findings.  I asked why he did that since I never asked for one.  Told me the office sent him to my property and he just followed his orders.  I called company and told them this but they said tenant authorized it and I owed them $400.  Asked tenant and they said tech tried to call me but couldn’t get me on phone so told him I had authorized it and so he signed for it.  Now I just received a certified letter from them saying if I don’t pay in 10 days they will place a lien on my house.  What are my options?  They obviously lied to tenant and he wasn’t authorized to sign anyway since I was the one who contacted the company.