Ease of lein for job that needed to be redone

I've been dealing with a company since March 2020 for shoddy window replacements. They never finished the install the first time and didn't get back to us for months. Eventually they agreed to replace everything. When they came back to our house, they did not have the right windows for the first two. The crew said they would contact corporate to come up with a plan. A month later we are told that they did their end of the bargain. We promptly asked them to accept our deposit so we can go with another company since their has been zero ownership of the issues. The company gets back to us a month later sending us a legal letter to collect payment and threatening us with a lein. They did not reinstall the windows because they did not have the right windows to install. How easy it for them to get a lein, considering we've paid them a third of what is due and they were supposed to redo everything. The contractual amount due was for a job, not an hourly rate.