I am in the loop as well. I've seen many, many posts about this. Here's what I've done:
- Restarted computer
- Tried different browsers
- Deleted cache and cookies
- Signed in to iTunes on device
- Reauthorized my device
- Double and triple checked that I had payment set up in iTunes.
- Tried to click on the "Contact Us" link in support just loops me back in to the original loop
- I don't have an iPhone so I can't "sign in with an iPhone" as has worked for some people. (If that's the fix, I guess I have to buy an iPhone, which would be completely b.s.)
This is a nightmare, a personal ****, and completely unprofessional at this point from Apple. This issue has persisted for months, with no error messages, no explanations, and no apologies. I'm extremely frustrated if you can't tell.