Can a pool cleaning service put a lien on my house. Without a contract?

If I am reading your question properly, this is a dispute over $95. If true, then I am unclear why you can't simply contact the vendor and negotiate some kind of a resolution. Do you continue to use them?Have you replaced them? Don't expend your valuable time stressing over this. Further, you say that the company replaced a skimmer basket. Even if you did not order it, it has some value, from which you are benefiting. If I am incorrect in my reading of your question, then please resubmit so that another reply an be provided.