@Dirk you are my resident legal expert from what I see on here,
Not at all, but I do play one on TV! I've taken the time (and stress) to go after others using legal remedies. And then I write about it here, that's all. I've won each time (but haven't always been able to collect). I've used demand letters, small claims court and my State's contractor license board. I've never used an attorney, nor Superior Court. But I'm in CA, which is very pro-consumer and has some very strict and all-encompassing contractor law that really helped my cases. And my damages in each case didn't exceed the Small Claims Court limit, so that greatly simplified things.
That's really your first step, is to determine what your damages are (or are going to be). Then that determines which court you'll be in, and whether you'll need an attorney or not. The amount of damages also helps you decide on what this is worth to you in terms of time and stress. Some of the cases I won were not worth it. Others were. I'm curmudgy enough to go after someone just for the principal, because while the stress is rarely worth it, the regret I would feel for not doing something would be worse (for me). You'll need to decide for yourself. Is the chance of getting a $2K check gonna be worth months of letter writing and a trip to court? Or are we talkin' five figures? And it's important to keep in mind that winning a court case does not mean you're going to get paid. That's a separate issue, and can be equally daunting. Here in CA, if you win a case against a licensed contractor, you can use the judgement to suspend his license. That puts him out of business until he pays. So that makes the success of going after a contractor more likely.
It sounds like you're in for five figures. So that's likely attorney-land. But if it's low five figures, sometimes only the attorney wins. Sometimes it's better to use small claims, even if the limit isn't going to cover everything, because of the difference you'll save not using an attorney. Ya gotta do the math (and stress is part of the math, as is likelihood of collecting).
I used the internet to figure out what I could and couldn't do, and how to go about it. Start there. See what you can learn about OH law and how you might leverage it. Do you have a state contractor's license board? Access to small claims court? If so, seek local small claims court advisors (here in CA they are offered by the State). Etc.
If your damages exceed the small claims case limit, of if you don't have small claims, then you're going to need an attorney, not me. But even if so, you can start with a demand letter. You can research what those are supposed to look like in OH. In CA they're suppose to contain certain components, which I learned about online. You can always hope that the demand letter, sent certified mail, is an eye-opener for the contractor, that you mean business. Squeaky wheel gets the grease dealio. That likely won't work, but you usually have to start with a demand letter anyway. Just be sure, if an attorney is in your future, that your demand letter doesn't somehow weaken your case.
Start documenting everything. Start communicating with him in writing only (no more casual visits to the office). You'll have to be able to prove what was said, when, by whom. Use Certified mail. Email is second best. Don't use texts. Don't engage him on the phone (avoid any unprovable he said-you said scenarios). If you do have personal meetings with the guy, have a witness present, someone not related or married to you. Have that person take notes. Follow up in-person meetings with a letter or email that recaps the meeting: "On such-n-such day/time we spoke about X and I said Y and you said Z." That sort of thing. Ask that he respond to emails with a reply, to acknowledge receipt. The first time he doesn't reply, stop using email and go to Certified letters only. He'll just say he never got the email.
Be prepared for a long haul. A lot of effort. And whatever stress this type of action generally brings you. Mine goes right to my gut, other folks are affected not at all.
That's off the top of my head. Good luck. Happy to help in whatever limited way I can...
