I think you need to ask yourself, "should I trust myself?".
When you sign a contract to purchase a car, on top of that contract there is a box that says, condition of car "new" or "used".
You assumed a 2011 you bot in 2012 was new? Clearly you didn't even ask. Who goes into the second or possibly the largest financial transaction in one's life just assuming things? Sorry but you have no one to blame but yourself.