Sorry, but I'm not surprised, as they told me something similar a year ago. What do you think you will do?
The black epoxy plan would be my choice, I guess. At least in that way you can bury weights in that cavity, come out with a near perfectly weighted set of heads and they would look reasonably good. Too bad you couldn't come up with something that says "Ping" on it to stick on top of the epoxy.....