From what I'm getting, you're already logged in to QBO. However, it's quite strange that you still got a prompt saying you do not have a subscription when you are at the point of entering your payment info.
About merging companies, we're unable to do this, but I'd recommend contacting our Support team to fix your billing details since they have access to accounts. Check out their schedule as well.
By the way, I'm not expecting, but in case this happens again, please do not subscribe to a new QuickBooks. Instead, you'll want to do the browser troubleshooting steps to see if the error is triggered by a browser issue. Also, our Terms say we don't offer refund or proration to the early cancellation of QBO, but I can see that your case is different. Our Support team will happy to check this out.
Let us know if you run into issues again. The Community team is available 24/7.
I had the same problem. Used the free trial and categorized hundred or so transactions and set up rules. I just paid for the subscription with the same email/login details and now I'm back to square one. I cannot access anything of the original account, just set up new. Please advise.
As I mentioned earlier. Login to your trial account and go to the menu Billing and Subscription. You have to pay the regular rate to continue your works. If you click the Buy button, you will open a new blank QBO account.