How can I report an iTunes billing problem?

Thanks, Carolyn, but the process described in that link is the one I've followed 50 or more times, and the message that I get is always the same:

"We're sorry but we're unable to complete your request at this time. Please try again in a few minutes or start over now."

To say that I'm going nuts is to understate the situation.

Thanks Carolyn. I contacted Apple, had to wait a day for the iTunes people to call back, then found that my report of a problem had been received 18 times while every time I was being told on the Apple site that the report had not gone through. I've gone through a similar process with attempts to book time at the Genius Bar, with dozens of slots "available" but none of them possible to book. I try to book at, say, 11:20, I am told that that time is not available, I call Apple and book at 11:20 with no problems. There would appear to be serious issues in both areas, but though I've reported the Genius Bar problem half a dozen times (by telephone and in person at the Apple store) nothing has changed.