What can I do if my baby will not take the bottle?

Have dad step in. Babies are much smarter than we give them credit! Your baby has probably realized she prefers the feeling of your breast to the nipple on the bottle. Given the choice, she is likely to choose you first! You might need to have someone else (dad, a grandparent or friend) step in to introduce the bottle when you step out. She will probably protest a bit, but will eventually eat when she is hungry.
Wait...try again. If your baby will not take the bottle it can be an adjustment period, an oral muscular problem, or the baby is not hungry. Let some more time pass then try again. If consistently unsuccessful ask your pediatrician for help or a feeding consultation with a specialist. If your baby was a successful breastfeeder, they just need time to adjust to the new change.