I have not had this problem with any American vendors or orchid sellers on eBay ... I have heard of vendors replacing plants for others if they no longer have what you have ordered .. I find it odd that they didn't inform you sooner as to the availability of the orchid you selected. In your case, a call might be in order and speaking to someone personally might resolve this issue - let them know everything from the beginning and perhaps they will allow you to exchange the orchid you wanted for one you prefer instead of just a 'substitute'. Good Luck.
Let us know how things progress
There are good European vendors quite a few here have dealt with .. I am sure someone from your side of the pond will let you know of some reputable ones