6mo won't take bottle

Introduce the bottle when she is not fully awake: try when she is falling asleep or just waking up, while dozy and disoriented. You may have to attempt this for several days.
Offer different nipples. Your DD may prefer one material (rubber, silicone etc.) over another. Generally speaking, a slow flow teat is good to start with, since she might get overwhelmed by the volume let through by a faster flow teat. Remember she has to suck pretty hard on your breast to get the milk, so she’s used to slow flow. Also sucking on a nipple and sucking on a bottle teat are not the same as the teat is much harder in their mouth.
Try a different style or brand of bottle.
Don’t wait until she’s hungry to try the bottle. Start earlier than the scheduled feeding so she isn’t frustrated and starving when experimenting with the bottle. You could try breastfeeding for a short time but not allowing her to fill up completely. Once she has had some breastmilk and is calm and relaxed, try switching for the bottle of formula.
Check the temperature of the milk. A common mistake is not warming it enough. Milk from the breast is 37ºC. Try different temperatures. Some babies may prefer a bottle cold or at room temperature.
Dip the nipple in breast milkto give it a familiar flavour and to encourage her to suck.
Start with 50/50 expressed and formula milk to begin with and gradually increase the % of formula. Mix the formula first, separate from the breast milk. Once the concentrated liquid or powdered formula is prepared, it can then be added to a bottle of breast milk.

Have you tried the MAM bottle?

We tried 5 different types before my son finally accepted this one!!