General Contractor charged crazy amount for trivial project

[Dennis Ulrich]

There was a small water leak under a toilet in a rental property I own. I asked a general contractor that I've not worked with before to fix it. We did not discuss pricing, and I instructed him to fix it and bill me, this is my fault. Because it was a trivial job, I expected a reasonable bill. When it was fixed, he came back with a huge bill, more than 2X what is normal. He claims that the plumber spent many hours on the job, but I know it's a lie because I have many other properties where the same issue was fixed for less than 1/2 of the price, and did not require much time. I learned an expensive lesson. What are my options in this case?