8 wk old on Enfamil Nutramigen, Diarreha/Vomit..Please help?

My wife and I have a 8 wk old daughter. She has been on Soy formula since her 2nd week. She is very colicky and we seem to have tried everything. She has a rflux problema and does not sleep very well at all. She also has long periods of fussiness and restlessness all day long. The Dr. put her on Zantac a few weeks ago and it did not help, she has also tried a thicker formula and all she did was spit it up or not take it at all. The Dr. just put her on the Nutramigen, now not only is she still colicky, she now has diarreha and vomits even more. He wanted to try the new expensive formula before prevacid. Nothing seems to work, Any suggestions on formula............................We have also tried gripe water, colic calm, and praying, all with no luck.