Well, first off this is not a bug report forum and McMasters does not read this forum (or at least not very often). There is a bug report forum on the the official forum and if you're having problems, that would be the place to report it.
One option, and if reading this leaves a bad taste in you're mouth, that's all right. It leaves a bad taste in my mouth for typing it. But one option you do have is to join BillyClub as you would have the option to turn off the capcha (or rather, render it inert. You'll still get the capcha, but put in the code, put in your favorite song lyrics, or even leave it blank and it won't matter. You'll still get in.).
The only other option is to report your problem either in the bug report forum mentioned above, or more directly by an in-game bug report.
Frankly, I'm not sure what can be done to help you. McMasters has no control over the capcha beyond use it or don't as it is a third party service. Even if McMasters does get in contact with the capcha service and something both can be done as is done, it is doubtful that it will be done expediently.
