Hello,
Thank you so much for getting in touch.
It seems you have successfully purchased an account.
Please install or update your Rank Math Plugin to the latest version: https://rankmath.com/changelog/
You can disconnect your account by navigating to WordPress Dashboard > Rank Math > Dashboard > Help and then simply disconnect the account by clicking on Disconnect Account.

Once you’ve disconnected your Rank Math account, you can connect it again in the same settings. In order to connect your correct account, click on Connect Now.

Once you click on Connect Now, please ensure that you’ve selected the correct account and then click on OK, Activate Now, as shown below.
Then head over to WordPress Dashboard → Rank Math → General Settings → Content AI and refresh the credits. Here’s a screenshot for reference:

Hope that helps and please do not hesitate to let us know if you need my assistance with anything else.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.