Voorkeuren en opties configureren in Outlook.com
I see. Try signing in on another browser and see if it export is completed and ready for download. It can be that the issue is the browser cache. Check if you received an email for the completed export.
If the issue is still the same and no email has been received, I suggest contacting the support for Outlook.com to help you further with the pending export.
How to get support for Outlook.com
Let them know that you have already waited for 7 days, which is beyond the maximum waiting time of 4 days.
If you require further assistance, please don't hesitate to let me know.