I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear that this happened.
You have two issues in this case. First, you'll need to establish that you only agreed to pay $1,500, not the amount he is asking for. You can testify that you told him you would only be able to pay $1,500 and that he refused to discuss anything else about the price with you. The fact that he did the work after you told him that was all you could pay tends to show that he DID agree - but you still have to show that you told him that. It would help significantly if there was anyone else who heard the conversation who could testify or if you had any emails or texts that discussed price before he showed up to do the work.
Second, if he did not do the work properly, then you have a defense against paying him. The way to show that the work wasn't done properly and to get estimates showing what it will cost to finish it. If what's there has to be pulled out and redone, get estimates showing that, too. That way, you'll be able to explain to the judge why you shouldn't have to pay the contractor. But you'll need that evidence, because without it, the judge can order you to pay the reasonable value of the work that was completed. If you can make video of the area, that might help more than pictures.
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