I agree with you, there should of been a heat pack included! That is very poor on their part and I would be disputing their claim that they always send tropical fish of any sort that way!
For the white spot my advice is don't do anything! White spot on marines is different to fresh water fish and in my experience it's best to do nothing and keep the fish as less stressed as possible!
Do you have another tank to put the fish in so the white spot doesn't spread to you other fish?
If it gets really bad then you can Google how to do a fresh water dip but trust me, if it's not affecting the fishes behavior then don't do anything to treat it and just keep the fish happy, it will eventually go away!