330cc overfilled to 500cc - is my very small chest wall the reason dr didn't use a bigger implant to achieve my goals?

330cc to 500cc is a rather large amount of overfilling during breast augmentation. Please discuss with your surgeon.

This question can only be answered by your surgeon. Perhaps it was related to discussions you had with her/him in the past. What sizes were you considering during your consultations? Your surgeon should be able to provide clarity on the selected implant.