Whenever I receive an SMS, the light will flash as normal, but I am unable to do anything on my BB. I press any button and nothing happens. This freeze occurs for about 30 seconds. This only happens, though, when I'm receiving more than one SMS, either from one person or one SMS from multiple people at the same time. After about thirty seconds, the phone unfreezes, though.

Can anyone help with this? I have tried pulling the battery numerous times.

You did not indicate how much memory is used or available for the applications to run. It does sound like it may be a memory issue or one of you apps is not playing nice. You can try reloading the OS to see if it clears. Or an ?Upgrade in OS level if older.

KB23391-How to check the amount of free space available on a BlackBerry smartphone