I agree with JHs. If there is no new color on it at all, just talk to the painter about it, if it was an honest mistake (which can happen very easily while painting) your painter should have no problem fixing it. However, in my years of experience, it is not unusual for 2 coats of door paint (good quality) not to cover very well at all. I once painted a red door 7 times, plus a tinted prime coat before I found the door to be a solid color.
This all comes down to the rules.....1. references....does the contractor have them??? I ALWAYS furnish all my prospective customers them....no excuses...2. insurance....again, I always furnish proof....3. Read the proposal carefully...I ALWAYS list materials down to tape used, the brand, the grit of sandpaper, the manufacturer, etc....its INEXCUSABLE to not list all of these items....I am a member of the PDCA, the Painting and Decorating Contractors of America, the foremost authority in the coatings industry and they also approve of what I listed....if you do not follow these guidelines, you will NOT get a job reflective of "professional". Look for the PDCA where any painting contractors are, if they are not a member, RUN!
IF the average cost is $1700 to paint an interior, then that means the cost of paint is approx. $200 (12% of the job). Or better said 5 gallons of paint (if the average cost is $40 retail). The average room takes 1.5 gallons which will cover 3 average rooms. Doesn't sound to average to anyone with knowledge of this industry or a average house. You are misleading consumers and should do a better job in your research. No wonder so pay people think prices to get work done by professionals is high. Its not high, its actually average which is more like $3700.