2013 370z electrical system locked? Car is completely dead!

Guitarded

Hello,

I've got an issue I'm not sure about... I'm not too mechanically savvy, just a Z owner. 2013 370z touring package (automatic). I came out of the store today, tried to open hatch, nothing. Tried to use fob to open door, nothing. opened fob, got manual key out, opened door, tried push button start, nothing. Tried turning on headlights, dome lights, hazards, still nothing. Figured battery is dead, called service, tried to jump, nothing. Tested battery, it's fine. noticed that the brake lights still worked when stepping on brake pedal, but pedal feels different... like its depressed to the floor. I tried inserting fob into provided slot (not sure of tech term) nothing. The car is essentially dead. can't get it out of gear, can't do anything, just had it towed home. I read some things about steering lock issues, but seems 2013 should not have that anymore. Any ideas? could it just be a bad fob? (I only have one fob) Is my alarm system stuck disabling everything? I need to get towed to dealer now (I'm out of warranty) and I'm hoping this is not going to cost my first born to repair, so I'd like to go in knowing what to expect, or what to tell them.

Thanks in advance for any replies.