If the door looks painted and is actually stained then way too much stain was used. I agree with Dave, these doors can look great either way- painted or stained. A stain will add color and highlight the embossed wood grain not cover it up and look like a painted surface.
Painter expectations- It really depends on what is on the contract. If it says "paint" then the painter is doing exactly what is expected and previously agreed upon. It is important to remember that the terms 'paint' and 'stain' are very specific to a painter and represent 2 different things and are not interchangeable.
The good news- All isn't lost. If you want the door stained then there are two ways to do it; strip off everything and start over or apply a satin oil base paint to act as the base color for the stain. Tan is a typical base color but depends on the final look you want. Old Masters sells base paints for their stains and their website is a good place to start looking for inspiration. Check out this page for ideas- <a href="//www.myoldmasters.com/products-faux-graining-base.htm" target="_blank">Old Master graining base</a>.