This is frustrating, I have been there with many patients. Try keeping her on a regular schedule of simethicone gas drops, this will help prevent gas pains before they start. Definately try to work up her hunger by changing her and playing with her for a few minutes before you try to feed her, this will also allow her to fully wake up. Make sure her formula is nice and warm, some babies will refuse formula that is not at their preferred temperature. allow her to suck a pacifier for 30 sec before offering her bottle to get her suck/swallow reflex going and to allow her to prepare to eat. If she still will not eat for you try using a new nipple, a different shape can help sometimes as well as a diff texture. Last try different burping methods, bouncing her on your knee while holding her facing down can help the hardest burps come out. Good luck and make sure to call your pediatrician if she does not increase her feeding volume in the next week.