It IS holiday time here in the U.S., so perhaps they've just been busy.
At the risk of sounding silly, have you checked the 2.5A fuse for the affected tweeter? I can't tell you how many times I thought I had blown a tweeter (on my old 2.2/Rs), only to find that it was a simple fuse issue. With a previous buggy amp, I'd sometimes have a channel go out, so had to do the whole cable-swap/elimination thing to debug the problem.
I only ask because you did not mention doing any of that in your original post.
I find that with the proper 2.5A fuse installed, it's actually pretty hard to trash the tweeter. YMMV, of course.