Lien threat

I hired a local landscaping company to do some work on my yard. They gave me a price, which I paid in full (I have the record of the cashed check). There was only a verbal agreement. After writing an unfavorable review of them, they are now claiming they could have charged me more for the work done, and are threatening to put a lien on my home. Do they have any actual recourse to do so? I’m in Rhode Island