Well I am the seller and I want you to be happy. Yes you need to water them once after they are potted. Only water them once though. Then place them in full shade and keep you fingers crossed. It sounds like they are beyond hope though especially with this weather we are having so I don't have high hopes for them.
On the bright side they will make a nice mulch for the new ones I'm going to overnight to you!
Did I mention how much the USPS sucks!