Put it inside a cooler to transport it back to the vendor. I transport mine like this all the time and no problems.
I would definitely depot the plant on getting it home and check the roots. Prune any dead ones and remove any sphagnum moss (The death knoll for phals)from around the roots. Repot in orchid bark and a clay pot. Now bear in mind that by doing this you will most likely lose any flowers and or buds the plant has, but it's a toss up. You either lose the flowers or maybe the plant if you don't check out the roots.