Adam, after chatting with you for some time about these fish before you even ordered them,I can imagine how you must be feeling.
I think the seller will compensate in some way.
Let's hope the ones remaining pull through.
They are a beautiful thorichthys species and I know through past conversations that you have researched them well.
They stand as much chance of bouncing back in your care as anyone's.
You still have a good number of them and they will probably spawn for you by next summer.
I look forward to seeing them grow into healthy enviable specimens.
Good luck and sorry for the losses.