I manage different accounts for different customers on ThemeForest with which I purchased many templates.
Today I bought a new template for Wordpress and I realized I had it with the “wrong” account. For the right billing I ask if it is possible to request the cancellation of the billing with the wrong data and redo it with the exact data.
Already purchased item billing information change not possible. if you like you can open Help ticket and let them know to get an official answer.