If the bike is unrideable, then either the dealer would fix, or you should get a replacement.
Are you unhappy with the MT09 fuelling generally, or is your bike a one off and has a real problem?
I dont know anyone who has ever returned the MT, if its broken it would be fixed under warranty.
I did have a mate who had a Mazda RX8 many years ago, which he did return under the sale of goods act, but that brake down 3 or 4 times in the 1st month of ownership, then the engine blew up. Obviously, his car wasnt fit for purpose