Being displeased with someone or their work requires that you first have expectations. If you haven't conveyed them in writing, you have chosen to take a risk. (You can't control other people and shouldn't try.) It can actually be a lot of work to be ready to hire someone, but I think it is time worth spending because of the education it provides. You may find that some contractors will not take the job if you want to do that, especially if the work is small, and others won't mind at all. The contract can also outline when you will pay (can be in installments) and what the evidence will be that the work, or each phase of the work, is done. It doesn't need to be a long document, but it should be written with enough detail that a judge will understand what the agreement was about. Keep in mind that it is rare that two people can share words and have each understand them the same way.
One consideration is whether you believe he is intentionally cheating people. Then you might have some level of responsibility to the community. Your evaluation that someone is incompetent, however, is not a matter for a lawsuit.
There is no reason to hide your unhappiness about your situation. Posting a photo of the shutter would be fine, but giving his name in public would definitely not be. If you feel that should be done, then you're really feeling like a lawsuit is justified. You don't want to get sued for defamation, even if you have evidence to "justify" what you claimed. Justification evidence is interpreted differently by every person.
Regarding lawsuits in general, in the U.S. there are certain things for which there are no procedures for you to obtain something you are promised or owed, and the proper action is to start a lawsuit. It is a way of involving a judge in the situation so someone will take a look at your circumstances, when there really isn't anyone in government who has the job to look at it for you.