Hi @baritalia,

I understand that you want to use the 2009 version of QuickBooks Desktop (QBDT) for Mac. And I'd like to route this concern to the best support who can help you further.

As mentioned by my colleagues and @qbteachmt above, QBDT for Mac  2009 version is no longer supported. 

Most of the unsupported license doesn't have any records. But to check if there are still records of the license number you've purchased, I encourage contacting our Technical Support Team. I understand that you've already contacted them before but they're the best support group who can help you further.

To reach them:  

1. Go to the Help menu.
2. Select QuickBooks Desktop Help.
3. In the Have a Question window, click Contact us at the bottom portion of the screen.
4. Click Search for something else.
5. Type in a keyword about your concern.
6. Hit Search.
7. Click on Start a Message.

You can check out this article for your reference: Contact the QuickBooks Desktop Customer Support Team. 

In case you need tips and related articles in the future, visit our QuickBooks Community help website for reference: QBDT for Mac Self-help.  

Please know that you can always get back into this post if you have more questions. I'll keep an eye out on your response.