KB23877 How to block incoming messages using the BlackBerry smartphone firewall
That should guide you to the proper location in your device interface where the blocking action would have been conducted...and you simply remove what you previously blocked.
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.