Help she won't take the bottle!

Hi all. I introduced a bottle of breast milk to my breast fed baby for that last feed before bed at 3 months. She had her ups and downs with it but we soon settled into a good routine and me and my other half could happily give it to her. We changed it to formula and she was happy with that. At now 6 months however she has decided that bottles are evil and wont take anything. Even breast milk. She had started chewing the teat and just doesnt seem to enjoy sucking, or won't even try to. Have tried all the tricks I can think of eg switching nipple for teat but as soon as she feels the plastic she pulls back. Help! ....................