It's not at all unusual to lose buds on plants purchased at that stage. The ones grown in your own collection are OK, and plants bought in flower are Ok, but in between - probably they are that much more vulnerable when packed up and shipped, and then asked to accept an environment totally different from the one where they developed. One thing orchids really love, is staying in the same place ; and the one thing they hate is being moved about. The only thing to do is be philosophical - cut the bad parts off, dust the cut with sulphur or cinnamon to prevent rot entering, and give the plant tlc - it will settle down all the quicker if not asked to carry those flowers !