IIRC security frozen state has to do with Secure erase. The FW should still be able to update.
What FW version is on your SSD? Can you post screen shots of the Dashboard showing the FW version?
if the SSD does not have any data on it I would try secure erase. Here is a KB article on the sandisk support site. http://kb.sandisk.com/app/answers/detail/a_id/16678/ scroll down to #2 for secure erase instructions.
