Sorry to hear of your trouble. Just to cover the easy stuff, when you plug the car in, do you have the key in the Lock position? If the key is in the On position, the car won't charge. Also, if you have the car unplugged, will it go READY (start)?
The AC and Heat are supposed to shut down when the turtle light illuminates, which means there is roughly 10% charge left in the battery. From this point until shutdown would take quite a while, not to mention running the 12 volt battery flat as well.
I'm not sure why the dealer told you to completely discharge the battery. Taking the charge down to 2 bars on the charge gauge is sufficient.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
"Photon" - 2017 Bolt EV LT in Orange with QC - 7/31/2017
Solar-powered since 10/10/2013