I did try to communicate in a couple of ways, through that form and through email. It appears that, just now, a refund has come through Paypal. I think I probably just need to re-do the upgrade process the right way.

I had asked for my subscription to be shifted over, but that might not be possible. Since the refund already went through, I'm guessing that a fresh upgrade is necessary and that it won't result in a double charge. I'll wait a bit to make sure all the dust has settled, then do that.

Thanks for you quick help.