Your radio is "bricked" . That's actually a cellphone term. It means that the phone has been converted to something akin to an actual brick. It can happen if a firmware update is interrupted. The problem is that updating the firmware is managed by the firmware itself. The most common reason for this is because power to the device was interrupted during the update process. But it can also happen is the update itself is badly written code. Given the reputation of this brand, that is the more likely reason. To put the quality in perspective, while the dealer will likely charge you $800 or more, I've seen the same unit on Alibaba, the Asian site that let's mfrs there sell to individuals here for less than $50.
Your only option is to replace it. I recommend you spend $150 or a little more for a better brand like Pioneer, Kenwood or Clarion. Sorry for your situation.