Why does my 3-month old baby refuses to drink milk? ( Will toss and turn and show distress)

Did she just switch to formula? Perhaps baby may also have bottle issues. Try changing formula first. If persists, change the bottle teat. She may feel the flow is too slow if it's level 1 teat (Level 1 is typically for newborns who are still breastfeeding while Level 2 for those on full bottle).