Accounts won't Merge

I have two accounts; the second one I never meant to be set-up, it was created by accident using my Google account to login. I've tried several times now over the last couple of months to merge the two accounts. I complete all the steps, I click the links send to the second account and click to agree to merging accounts, and there's a notification that this is processing and will take some time; and then nothing. The two accounts continue existing separately.
I've made sure both accounts are properly setup with their unique passwords, in case that was an issue for reason (that an account logged in using Google or Facebook or something and didn't otherwise have a password set for it could cause conflict or not be considered a proper account). I've tried logging into the second account when I accept the merger, in case that was necessary.
What am I missing?