M.S.
I got my son to take formula by mixing mostly bm with a small amt of formula at first, then after he took that I'd just increase the ratio of formula to bm and he took it no problem--it took a while, but he was able to get used to it at his own pace. My daughter was more challenging. She didn't want it at all. So, I took a break from trying until she was a bit older and tried again. Once she was used to the bottle and didn't breastfeed anymore she was willing to take it--She loved it. She drank formula until she was almost two. My advice would be to take a break and then try it again later. Hope that helps.
mb