Terrible news for anyone who has been following my replies which indicated it was "fixed"
Short of the long is, its back.......
And the culprit was AGAIN a community event. This time the Magikarp (originally it was Ghastly). Basically TWO purchased for the 99cent event. First failed. Second "worked" on Thurs.
Today for the first day I attempted to buy coins since GoFest. Purchase to buy coins returned the dreaded error. Now account is broken again. Worse news is, the "fix" I tried before did NOT work this time. Sucks.
One interesting experiment this time that I didn't do the last time - after the issue returned, I deleted ALL payment methods from my iTunes account. Logged out of my iTunes ID. Went to PoGo and literally clicking on buy something returns the error.
Why do I think important? Because I now believe the issue is 99% Niantec's and not Apple's. I never got a message like "hey idiot, you aren't logged into iTunes" or "hey idiot, you don't have a payment method associated to an iTunes account."
I randomly then went into the Apple App store and tried to buy a random app. And guess what, you get both of those messages that you aren't logged in nor have a payment method.
So, I believe Niantic is the problem. And i hope the fix it :(