After syncing, it should go down as it also contains the crash logs that are transfered to your computer during a sync. This is in addition to any data that gets stored. Sometimes a reboot also helps after a sync. Hold your on/off key and home key for 8 to 10 seconds until you see the Apple logo. Keep in mind that some amount is normal and it will depend upon what type of apps you have and what they need to store to keep track of your history.
For service or support questions including existing order status, call: Customer Support: 1-800-331-0500
Information on iPhone unlocking can be found here by copying this link into your browser: https://www.att.com/deviceunlock/client/en_US/