Combination feeding of breastmilk and formula milk

Hello po! Ask ko lang po if ano pong ginagawa nyong way para dumede si baby ng formula milk? Pinainom namin enfamil A+ pero nagiging fussy sya. LO is 2.5 months old. Nagpupump din kame ng breastmilk and wala syang issue sa nipple or sa bottle feeding? Ano po kayang maadvise nyo na formula milk?