transition breastfed baby to bottle

Hi mga mommy. pahingi naman po ng tips kung paano itransition si baby sa bottle. 5.5months na po si baby & ayaw nya po magdede sa bote. we are using Avent Natural bottle & teats. we have already tried the following but nothing worked. 1. change teat flow of the bottle 2. giving pumped breastmilk sa bottle 3. tried giving it at night habang bangag pa sa tulog si baby 4. tried na si hubby ang magpadede 5. 5hrs ng lumipas pero ayaw pa din talaga magdede other bottle brand na lang ba talaga ang option? if yes ano po marerecommend nyong brand.