Do you know what products were used? I know, for example, Polycrylic (water based) specifically states not to use over red mahogany stain. I think the red mahogany issue goes the other way of losing the red, but it could be a similar issue that the stain and varnish aren't compatible and cause the color to come out differently.

I will say, if you're going to approve a color, it is best to make sure that you see the fully finished color: stain on the same type of wood, applied how it will be applied with all coats and finishes. That way if the color will be affected by the finish or sheen, you'll have seen what should end up on your piece.

I can believe that the correct stain was used based on the pictures, as there are red tones in that brown, but varnish shouldn't change a color drastically if done correctly. This is, however, fixable. We had window trim take a stain super orange, and it was corrected with a tinted varnish (as it already had its first coat of varnish before we saw the orange). You could probably have the brown added back to give you more the color you wanted.

No, the carpenter is very vague about all of this. I'm just very frustrated because I feel like I'm being played and that I've thrown away my money more than anything. The carpenter is saying than nothing can be done about it except making the wood a darker color, which I did not want.

He said the furniture would be delivered tomorrow. Let's hope for the best.

You can neutralize the red with a raw umber glaze or toner.

Either is added during the finishing process anywhere after the staining, though glaze needs to be locked down with another coat of clear finish on top.