I too would suggest another vet - why he would NOT want to see them is a real mystery. Also, definitely find out all you can about bottle feeding.
I tried this once many years ago, all the babies were lost. I didnt have all the info I should have, though may not have changed the outcome.
There is what's known as "fading kitten syndrome" that sometimes claims all the babies - for reasons that are unknown. As LR says..in spite of every attempt to get them through, there seems a type of genetic "flaw" that causes a failure to thrive. It's very heartbreaking to witness them weaken and die one by one. :sad:
Good luck to you, I truly hope the one remaining male will pull through.
Bless you for helping these poor little ones, and trying to give them a chance.