So this isn’t the usual type of thing that I like to write about, but I’m a huge fan of making knowledge publicly available, so here goes.
Recently I changed the email address on my iTunes account. After that happened, and after I’d verified, I wasn’t able to sign into iTunes. I kept receiving an error message saying that my email address wasn’t verified, and to click OK for instructions (which never happened). After clicking OK, I’d get another iTunes error message, 5002, saying the store was unavailable. This was really weird to me because I could still buy & download application updates via my iPhone (same iTunes account) but not thru iTunes itself.
Ultimately, I tried My Apple ID. From there I logged into my account and noticed that my primary email address was unverified, but the secondary email address was verified (and the same address as the primary). I found that I was unable to resend the verification email for my primary address, so I deleted the secondary (duplicate) address which allowed me to resend the verification email for the primary.
From there, I was able to properly verify my primary email address, and resolved my iTunes 5002 issues. I hope this is of some use to someone, out there on the Intarwebs.