MPC uses Meyer (maybe other hatcheries as well, certainly Ideal is possible). I'm sorry you got shorted your Buff! I know how sad that is when you have your heart set on something. Maybe you can find one locally? They are pretty common birds, so maybe someone near you has some. I will say that I have ordered from MPC twice with mixed, but good results. The first time I ordered 15 bantams. They sent no extras and I lost one the first day and then a couple more over the next 2 days. Of the remaining birds, a few had to be rehomed as they were roos. I decided to order again this year from them because they had some breeds I really wanted that are hard to get.
This year's order was better. I ordered 25 chicks. We lost two the first day, but it was horribly hot when they were shipped (100 degrees). They sent several extra birds this year though and all the others have been healthy as can be. I wouldn't hesitate trying them again, especially if you can only do a couple chicks. Did you ask if they can do an order of only a couple chicks as replacements? If they can, maybe you can do that and sell the extras. Just an idea. Good luck!