What can I do about formula?

Tierra • Mommy of a 🌈 baby

In my state, wic only gives Enfamil. I’ve tried all the different brands of it and my son hates it. So far he’s only been able to digest Similac Pro Advance (which is so expensive 😩)I even got my pediatrician to write a note saying Enfamil upsets him stomach but wic still will not change it. Are there any other options I have? What else can I do?