I've also created a thread about my case here: [https://developer.apple.com/forums/thread/819149#819149021]. Hopefully Apple addresses this for all of us.

Hi Tony, To answer the reason why the Apple Developer App says the enrollment is not available was because your account is not an individual account, it happens on my end as well, Companies account enrollment needs to be completed via Web... In my case, it's actually been a month ago I've been facing this same issue of failed payment, and it's so frustrating honestly. I've sent tons of messages via support ticket multiple time but no response while payment keep failing silently. Meanwhile I've tried to use different types of cards which is costing me silently but still it's not changing the situation... Just like you stated, I am stuck and ran of options as well -- which is the reason why I'm here hoping to figure out some useful tips.. Should you finally bypass this, please do get in touch I'll be glad. Thank you... Btw, I've seen a lot of dev having same issues, it was on Apple system I bet...