From the GM's response it doesn't seem like Kris was a total douche. He was probably just teaching you on a set curriculum that has achieved success for many students in learning to become efficient snowboarders which was probably how he was taught to teach. Your frustration in my meek opinion came from him not relating to you directly and tailoring the lesson to where you were at specifically. It sounds like they have a set routine they take all new students through and you can either follow their program which will no doubt help get you off your backside and down the slopes or (which I did) have one lesson from the resort staff and then go it alone. I progressed ok but had so many road blocks. I only really progressed fast when I had some advanced riders be patient enough to take me riding and provide instruction.
You will no doubt become a good boarder as your frustration is a response to how determined you are to advance. I'd take another couple of lessons and then just hit the slopes with your mates (buddies) and that girl you mentioned.
Don't worry too much about the difficult terrain as when you do go to other mountains you will kill it. For my first year I thought snowboarding was actually iceboarding (coronet peak NZ - They call it concrete peak).
Good luck and let us know how you go.