How do you take legal action?

[Aroldo Villarreal]

I hired a contractor to rehab a rental home I purchased back in September. For no reason, the job took two weeks longer than expected. The tenant was scheduled to move in on November 1st and he told me that the job was going to be done no later than October 31st. Originally, it was supposed to be done on the 15th of October, but took two weeks longer. November 1st comes around and I show up to the house and it's not finished. They are working as fast as possible to finish at least the inside so that the tenants can move in.

The contractor assured me that everything would be done on by that day. I'm a teacher, so it is hard for me to get out to the home and check on it daily. Anyway, two days later he came to pick up a check telling me that everything was done. Me, being new to RE investing, being naive as well, gave him the check without checking first. Also, in hindsight, I should have also made him sign a contract stating the date which he would be done and also charging him for every day he took after that to complete the job. 

It has been a month and a half now that he's been either avoiding my calls or telling me that he's doing it on a certain weekend and now he doesn't show up or answer his texts or calls on the day he is to show up. I'm fed up with it. What can I do? Do I have to hire a lawyer and spend days in and out of courts? The total estimated job left over should be under $1,000. I have to say between $500-$800. 

Any help is greatly appreciated!