This is an accepted solution.
Ash here from the Shopify team. Welcome to the Shopify Community!
I understand you're having some trouble accessing your account after trying to add your billing information. I can see that you've already opened a support ticket regarding this case, and that is the correct next step in this situation. In order for our team to determine what's causing this issue, we'll need to take a closer look into your account. This requires us to authenticate you on the account in question. At this time authentication can only be completed via email, chat or phone since we can't share sensitive information over the Shopify Community Forums. That said, the best way for you to receive support with this issue will be to wait to hear back in your open support ticket.
For anyone else experiencing a similar issue, in order to receive assistance the best course of action will be to visit our Help Center, and start a conversation via email, chat or phone with one of our Support Advisors. They will be able to further assist with these types of situations. While there may be times when the phone option is not available due to business volume, our chat and email options should remain available 24/7.
I hope to see this all sorted out shortly for you!