Formula help

My baby is a month old. We've been having formula issues. She has bad gas. She was on the similac advance. I tried the sensitive and it made the gas worse. I went to her pediatrician and she suggested alimentum. So we tried alimentum....she's only been on it a day and she enjoyed the pre-made stuff but when I switched her to the powder she started screaming. She refuses the bottles. It got so bad today I gave her a bottle of the Similac Advanced because she's so hungry and I can't watch her starve. I hate switching her formula again but she refuses the alimentum and I didn't know what else to do.

Anyone else have any formula suggestions for a fussy baby?