Please Help Baby Refuses to Eat

My sweet little girl will be 3 months on the 18th. For about the past month it has been a struggle to get her to eat. One day she wont fight too bad, but then the next she will fight with every ounce of her being. Her Pediatrician said she has to eat 30 ounces a day, but I'm fighting to get between 15 and 24 in a day. She will scream when you take away her paci and put the bottle in her mouth and she will refuse to suck. Shes been on the same formula since birth, similac pro sensitive. I feel like I've tried everything, but does anyone have any tips?