Hi Shayna, welcome to the board! Congrats on your twins! :)
It seems like she could be having an issue with the formula. Since I didn't go through that I'm not sure what the steps are. I would talk to your ped again and be persistent, maybe she is lactose intolerant..
In the meantime what I have heard that helps with the gas and the pain is to place her on her belly when she is napping and you're around to watch her because the heat will help break up the gas. Also using your palms and placing them on her belly can help as well. There is always gripe water as well, you can give it in the bottle or by a dropper.
Some of the ladies on here have experience with this and I'm sure they will chime in as well, hope this helps for now, good luck and keep us posted! :)