We were able to duplicate your problem by creating a folder on the root level of the disk and preceding to make new folders until we had a folder with 100 folders. Get Info on the parent folder showed 99 items.
The folder can be deleted as follows:
1) Opening the parent folder.
2) Choosing view by name.
3) Option-click on the triangle to display the entire hierarchy.
4) Scroll down and to the right (folders nested this deep really cause the
Finder to indent).
5) Trash the folders from the bottom up.
This does not have to be done one folder at a time, you should be able to delete at least 50 or more at a time.
Support Information Services