2012 Nissan leaf head unit not working

So I turn the car on it says Nissan. Navigation with black screen then goes black and then blue screen appears saying no SD card i took it to dealership they say it won't let them reprogram the SD card and that the obd2 is says it has a system malfunction it's 4200 dollars to replace the head unit the car is not worth that the part is 3000 please help me fix this I can't afford that I just brought the car. Dealership aslo said they unplugged and replugged in the unit. However I have this sinking feeling they didn't even touch the car as the head unit looks like it's never been touched like the seals are still in place

Forget to mention it won't let me go to any other screen at all

Is the SD card in place? Did it quit working suddenly? The head unit will not function without the correct SD card for the car so you may need to purchase a new SD card programmed for the car through Nissan.

I will buy new ad card and will update with results

It certainly sounds like a 2nd opinion is in order. Even if the proprietary SD card / card reader is defective I hope that an ebay unit along with a dealer programming charge could do the trick. Everyone has been saying for a few years now that we are approaching EOL for all the electronic crap that's been put into modern cars. Scary $$$ times.