Problem with a contractor

[Kendall Mercer]

So I recently bought a SFH to rent out and just had it remodeled. The guy I hired I asked to do a laundry list of tasks which included painting the exterior. That same day I contact him for the job I had told him I wanted white trim, a yellow door and black shutters. I don't hear from him for a couple days and am assuming he should be getting close to finished on remodeling the inside of my house and starting on the painting of the exterior so I send him a text detailing what I wanted with the colors of the outside of the house. Just to make sure he remembers. ( This is the second time I told him what colors I wanted) The following day he tells me he already painted the house back to the original colors. I told him that is not what I had asked for and he says that I had never told him what I wanted so he just painted it back to the original colors. Of course he is wanting me to pay him but its not what I had asked for. I'm new to this so is it normal to hire a contractor and he just decide on what colors to paint the house for you? Even if I hadn't told him what colors to paint the house shouldn't he not have just decided on his own to paint it the original colors of the house? That completely defeats the purpose! What would you think or do in this situation?