This problem comes up when running Oracle XE Edition which is intentionally crippled to fuck with you.
Hate Oracle databases so much.
Find out the current tablespaces raw files. You will need rights, but since this is Oracle XE you should be able to grant or log in as system
select file_name from sys.dba_data_files;
Now for example increase the User DBF file
ALTER DATABASE DATAFILE '/u01/app/oracle/oradata/XE/users.dbf' RESIZE 2000M;