Correcting Radiesse Underfill?

I recently had Radiesse injections in my cheeks. Now, three weeks later, it appears that the right cheek is indented and not quite as full as the left cheek. I will not go back to the original doctor that did the injections as I feel that she is less than qualified to perform any cosmetic augmentations.

I am wondering, when correcting an underfill, do I have to purchase an entire syringe of Radiesse, or is it possible to only pay for exactly what is needed to correct the problem? I would think that the company that manufactures Radiesse would want happy customers and would accomodate such a request. Thanks.