Baby refusing bottle

Hi mommies... I baby is 7 months.. pretty under weight... Completely on formula and refuses to haveilk after first 2 ounces then I am just forcing the bottle in her mouth and she is only crying or spitting out themilk ... And rightafterif I try feeding her with a spoon she has it ... Had this happened in your case !? What should I do.. completely get ridofbottles and just feed a spoon by spoon... Which can be really long and tedious ... But I guess you gotta do what you gotta do ... ???