Keep a close eye on them...
We had a couple kittens a few years ago that we took in at around two-three weeks old and about the same size; they hadn't opened their eyes yet due to eye infections. The mama wasn't keeping them clean and that was why we took them. Regardless, they needed food every two to three hours because they were sick; we took turns getting up in the night and used the kitten milk replacer, KMR, that Petsmart sells. We used a bottle at first and switched to syringes after the little boy kitten had chewed off the tips of all the nipples. They were weaned at 5-6 weeks.
Can you maybe get a dried formula mix from your vet? Or would he not take calls early on a Saturday morning? Right now, they really need the milk...even goat milk or baby formula if you cannot get kitten formula.
There's a recipe here and lots of information:
http://www.homeatlastrescue.org/html/aboutcats/kittencare.htmlI hope this helps you, and I hope the kittens are all okay.
And I should have added to weight them if you possibly can. I know with our peachick that died that if we had been weighing it daily we would have been aware of its weight loss and maybe been able to save him.