Because it's the weekend and officially tickets are only handled during working hours.
However, I have replied to the ticket but I can only really point you to this post from Mike:
There's nothing we can do from within XF to resolve the issue - it's something your host will have to address.
The physical files are stored in the file system.
The location is based on the user's ID - https://xenforo.com/community/data/avatars/o/0/521.jpg .
Members with IDs 1 - 999 are stored in directory /0, IDs 1000 - 1999 in directory /1 and so on.