You are still under warranty. Call Apple Care.
#1 - You have 14 days from the date of purchase to return your computer with no questions asked.
#2 - You have 90 days of FREE phone tech support.
#3 - You have the standard one year Apple warranty.
#4 - If you've purchased an AppleCare Protection Plan, your warranty last for 3 years. You can obtain AppleCare anytime up to the first year of the purchase of your computer.
Take FULL advantage of your warranty. Posting on a message board should be done as a last resort and if you are out of warranty or Apple Care has expired.
before all try in Preferences - Energy saver - disable automatic graphics switching. It should force discrete card.
Also Utilities - System Information - Graphics/Displays will show you how much kards you still have and to which of them display is currently attached
Also bootcamped windows uses only discrete card if it exists - so if you have it you can check what windows will show about gpu