Don't be sorry, you've done nothing wrong.
For most people, 600cc is plenty, and they can hop in a taxi and get their implants done. For others, 600cc is just the beginning, and it take years of research and vetting to nail down a practice that can help them achieve their goals.
So far there is only one doctor in the world that I am sure can give my girl an upgrade using silicone, and his office happens to be 20 miles from me. I suspect there are doctors in Europe and South America who will do this as well, but I still haven't heard anything definite (so I am asking for help).