Keep the babies in a safe warm place, not around momma. Bring them to her (or her to them) twice a day. Assuming they are in a nest box, pull the babies out of the back, towards the middle/front of the box. Hold the mothers head and belly and place her on top of the babies. They should start nursing. Her milk may not drop right away, give her a few minutes. You may have to hold her head to keep her from biting at the babies. They should nurse and be done in 5-6 minutes. Take Momma out, return her to her cage space. Check the babies to see if they have plump lil bellies... they should look like they swallowed a ping-pong ball.
Do this twice a day (early am and late pm). As the doe gets used to it, she may be more willing. But be careful. She can do a lot of damage if you are not watching carefully, and she decides they are bothering her. I've had some does "change their mind" and actually accepted them after a week. But if not, you have to assume they will need feeding for at least 4 weeks.
Don't be in a hurry to use a replacement formula. If you can get her to cooperate, it will be better for the babies.