Paying for Botox by the Vial

First of all, you did not have 3 cc or 6 cc of Botox - they would be way off the chart.  I assume you are meaning to say 3 units or 6 units were injected in your crow's feet, which is usually about 1/10 of a cc.  In my practice, we charge by the unit so that you know exactly how much Botox you received.   Good luck.

It sounds like your physician is trying to hide the number of actual Botox units used by selling it by the CC. This is a common practice to dupe consumers about the amount of Botox that is used.
While you may be able to request your medical records to determine how much Botox was used, it may not help you recover any fees you paid. Our suggestion would be to go to a practitioner that is fair and open with the amount of Botox UNITS that are being injected.

This sounds very strange to me. First of all, there is very little way that anyone could ever require an entire vial (100 units) of Botox to treat their crows feet, regardless of how severe those lines may be. More concerning to me is the refusal of documentation regarding your treatment. You should always have access to the amount of treatment you received and are completely entitled to know the number of units (regardless of how it was diluted into cc's) used.
In addition, you should not be forced to pay for the remainder of an unused vial of Botox (which it sounds like happened here). In my practice, we charge by units, as we feel it is the most accurate and fair way to determine reimbursement for a dosed or measured treatment (such as Botox). Other practices do charge by cc or by area, and although these methods are somewhat less accurate, they are by no means wrong and are in widespread use. Charges by the vial are more unusual as 100 units (a full vial) is a lot of Botox for one person at a time. One notable exception may be for the treatment of underarm sweating, which does require about 100 units for a complete treatment.
You may want to look for another doctor, one who respects you and your loyalty a bit more and one who will be up front with you regarding treatments administered to you. Make sure they are board certified in plastic surgery or dermatology and that they perform Botox injections regularly. Good luck!