Hi, mulkeyusa! Are you able to access the internet?? Since MMS also uses the internet to send/recieve, iIFyou cannot access the internet, there could be a possibilty that it may be blocked.
Have you emptied your inbox/outbox?
If you are the account holder or an authorized user on the account, you can also contact CC at 1-800-331-0500, from a phone other then your Quickfire, and have them check to make sure MEdia Net is enabled for your line of service. They may want to send you a TEST message and do not hang up with them until your phone is working as it should.