Hello,
Thanks for contacting us and sorry for any inconvenience that might have been caused due to that.
We have merged the purchase to the correct email address. Please reconnect your website to your Rank Math account by going to WordPress dashboard > Rank Math dashboard > Help > Disconnect and Connect.
Then, head over to Content AI and refresh the credits count so the plugin will request the updated credits from our server:

And you can also download the invoice now from your Rank Math account: https://rankmath.com/my-account/subscriptions/?tab=payments
Hope this helps. Let us know if you need any other assistance.
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.