I am owed more than $9,000 for a house I was working on. My family contracted Covid and was placed under quarantine. I notified the homeowners about what was happening, they said they didn't care if we were under quarantine, they wanted it finished. I went back to finish about 2 weeks later to learn, they fired me and didn't want to pay me for work I had already finished.
You state you were fired from a job and not paid for the last $9,000 of work and materials. If that is correct, then you are entitled to several remedies:
The strongest part of your case is payment for work-in-place: the Mechanics Lien claim and a claim for unjust enrichment. Your chances under a breach of contract theory are not clear - the Court's have not yet ruled that COVID is the kind of unavoidable "Act of God" that can excused contract non-performance. But you can certainly try.
I hope this information was helpful. I recommend speaking with an experienced Construction Attorney about your options. Best of luck.