I checked your account and noticed that you ordered 50GB storage space; you also ordered 10 user licenses. You allocated about 4.8GB of storage space to each sub-user. Thus, your remaining storage space is very small.
Please note when you allocate storage space / download bytes to sub-users, it reduces your own account storage space and download bytes. You can re-allocate storage space and download bytes from your Group Admin page. Just select a sub-user and click on "Set Storage".
You can also let all group members share the same 50GB storage space and 200GB download bytes, which will be described later. By default, all sub-users have their own private "My Storage" virtual folders. Different users (or sub-users) have different "My Storage" virtual folders.Each user (sub-user) also has his/her own default folders / files such as the "My Documents" folder. If you don't need these default folders, you can logon as the sub-user and delete these folders.
To share the same storage space and download bytes, you need to use Share Folders. Using Group Admin tool, you can reduce the max storage space and download bytes to a very small number. Then you can create folders in your own account for your sub-users, e.g. create Folder1 for User1, Folder2 for User2, etc. ; then share FolderN to UserN (with the right permission).
This way, when UserN logs on DriveHQ.com, he/she can see the shared folder in the special virtual folder:
Each sub-user can only see folder(s) shared to him/her.
When a user / sub-user uploads / downloads files in a shared folder, he / she uses the folder owner's storage space and download bytes. Thus the sub-user doesn't need to be allocated with a lot of storage space and download bytes.
(BTW, to make the sub-user account less confusing, you can delete all folders / files in the sub-user account's "My Storage" virtual folder. )