OK, Coming into this post late but if you haven't resolved this issue..try the MAM ultivent bottles. They are completely different than anything you've seen before.The nipples have 2 flat sides that have a soft "skin" like feel. DS#2 absolutely refused all bottles. My first day back at work i was gone 11 hours. During that time my stepmom managed to get him to take 2 ounces of EBM. Needless to say I was going crazy! You can't buy them in the stores but I found them online at baby-wise.com.
Also, they are distributed through the brand name sassy and for awhile they were giving away free bottles to get people to buy them..
I can't recommend them enough for breastfed baby....
Hope this helps!