Bought theme does not appear in “My account”

Hi, a few months ago, I bought your themes "My Music Band Pro" in Version 3.0. I now wanted to update to a newer version as version 3 has some issues with the sorting of homepage entries which have already been solved in Version 3.3.4. But my purchase does not appear under "My account", and I don't want to buy the theme again to get the newest version. What can I do? Can someone help, please?