I purchased a Modern Warefare 2 bundle pack from Best Buy. The pack included the Modern Warefare 2 video game. I went to exchange the video game (just the game itself) to update to the Hardened edition. Expecting to be in and out of the store in minutes the Best Buy customer service person made a huge mistake.
She refunded me 200 $ on my Best Buy card and and gave me 116 $ in cash (she refunded me for the whole system). All I ended up was paying 80 $ for the Hardened Edition of the video game its self.

Now Best Buy keeps harrasing my phone and has gone as far to tell me if I don't return to give them the 116 $ back they will consider it THEFT.

Question is : Could I be punished for there mistake?
yes... I know this is dishonest on my part (not to return there money) but if there is no legal ramifications on my part whats the point?