You need to take action:
1) Keep checking Enrollment Services Online , Course Listings or the VIP (713/743-8484); a new section of the course may have been added, or someone might have dropped the course.
2) Call or stop by the department offering the course to ask if any additional sections are likely to be added; if so, when? Is there a waiting list?
3) Schedule a course that would be a good alternative; consult with an advisor first.
4) Wait until the semester begins. Many courses will have space available within the first week of classes. Attend the class you would like to enroll in even if you haven't been able to enroll in it. That way, you will be sure you really want the course, and you will not have missed anything if the course becomes available.
5) Ask the course instructor to sign an add/drop form giving you permission to enroll in the course over the quota. Be sure to follow departmental and college procedures in using this method; not all departments authorize their instructors to do this. If the department/college does process your request, double-check your schedule to be sure that the course you added doesn't conflict with other courses already on your schedule.
Don't settle for courses that are not appropriate just because they are available. Keep working on your schedule until you are satisfied with it.