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

Modest overfilling has been shown to produce a protective effect in reducing deflation rates. See my published article in the link below. Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author. RealSelf Distinguished Hall of Fame Inductee. Philadelphia, Pa., USA

There is really no excuse to overfill a 330 HP implant to 500. Could have used a 420-500, 460-550 or 500-600. The surgeon most likely did not have the correct implant to use.

Dear jessieb0118,
I understand your concern. However, without a proper assessment, it would be difficult to determine what is wrong. It is best that you visit your plastic surgeon for further assessment or ask for a second opinion. Only after a thorough examination, you can get proper recommendations and advice.
Daniel Barrett, MDCertified, American Board of Plastic SurgeryMember, American Society of Plastic SurgeryMember, American Society of Aesthetic Plastic Surgery

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.