pebble, my gal is 7 weeks old... she was on TBF for 4 weeks before I intro bottle... I also had the same problem and had to suffer repeated comments from my MIL re my decision to intro bottle "so late"? luckily, my parents are more supportive and they helped me to train her to take the bottle during the long weekend last week... it's been 1 week since she willingly took bottle in the day and only latch at night... so far so good...
Initially, it is advisable for you yourself NOT to feed bottle as your baby will smell your milk and automatically turn to your breasts... get your hubby or someone else to do the feeding...
Second, you have to be assured that bottle rejection is NORMAL becos your baby has recognised her source of food, which is your breasts... until she also start to learn to recognise that the bottle is also food, she will start to suck from bottle as well...
Third, you have NO CHOICE but to withstand heart pain when hearing her cries... unless you are ultimately willing to quit your job to nurse her full time... for me, I decided she HAS to learn the bottle and she has NO CHOICE... so I tahan her cries...
learn how to calm your baby down WITHOUT offering the breast is very important... cos previously whenever baby cries, i feed her thinking that TBF = upon demand = when cry... but this is not true... sometimes baby jus want to sleep or bored... so i learn to calm her down without latching her...
What my parents did was the cold turkey method... very cruel but effective... during the day, she either no milk or take bottle... first day will cry a lot and take very little bottle... DO NOT offer to latch as your baby will learn that by crying very badly, she will get her way and be able to latch on you... second day, she still cry when given bottle but ultimately still suck... third day, she still cry but lesser...
btw, i also first used avent... then tried nuk latex... when i confirm she can take bottle, jus a matter whether she wants or not, i gave nuk silicon... after that i switch back to avent... i still feel avent is the best cos it does not leak as badly as when i use nuk... and my dad and hubby commented that the way she sucks is the same as at the breast...
i wish you luck...