I'm not going to follow up with my plumber to pay him
Why don't you wanna pay him ?
I don't think he did a good job.
If you agreed to pay for services, you should pay what you promised or face legal issues. If you're not satisfied with the service you got, talk to the plumber and work it out that way.
What if I don't care about these legal problems because I have rather serious issues I'm dealing with right now.
You have certain problems doesn't mean you should avoid paying the plumber. As I said talk to them and sort your the issue out instead of refusing to pay.