Car died! Not the battery. ALL dark. Had to lock and open with key. Had to be towed to dealership. Now day three without car. What is the problem??
You should be asking the shop because without seeing the vehicle in person no one can answer that question .
1). The dealership will tell you what the problem is when the diagnosis is complete. May take a while, they may be backed up with other cars in for service.
2). How do you know it is not the battery?
I believe on top of your battery there is a fusible link/circuit breaker that looks like the picture below. If you are not getting any power to anything, then this can be blown. but if you are getting some power then you have a different problem.