wood floor store filed a mechanic's lien for not paying bill but did not supply a NTO in state of Indiana

Hello- A flooring store supplied and installed engineered wood in our new construction home. They did shoddy work on the steps and agreed in writing to have the stair treads removed. A few weeks later, they told us to pay them 19K for their work. The what we believe was an inflated bill was written on a post it note and not itemized. We told the store we would not pay in full until the stair treads are removed as agreed upon. They then stopped communicating with us despite our texts, emails and certified letter stating we'd like a detailed invoice itemizing costs (not on a post it note) so that we could settle our bill. Lo and behold we then received a mechanic's lien on our property. We are in Indiana and never received a NTO from the flooring store. Could this lien be without merit a result? Also, side note, the lien was originally sent to the new construction home which doesn't have a mailbox. The county then sent it correctly to us but not regular mail, not certified.