My condolences on your situation. However, I believe you are SOL in this situation.

There is nothing wrong that Hertz assigns you a vehicle with commercial plate. In fact, depending on the state of registration, registering a rental car as commercial can be mandatory or optional.

Also - NYC is what makes everything way complicated. NYC is known to have its own rules, even from NYS.

Bottom line, by going to the NYC, you have only yourself to blame.