the MagSafe Charger for Macbook Pro 15inch (A1343) exchange??

Hi,im a macbook pro 15 inch user, and i bought mine in November 2010,

so its a 2010 model, obviously..

anyway, i have a apple care and it will expire on the 26th of November 2013, as i just checked

my magsafe charger (A1343) has a rip in the chord and i dont know how this happened.

all i can tell you is that i have been taking so much care for my macbook, as i tried so hard to save up money to afford it.

i live in Australia and there arent ANY genius bars in the state that i live in, which is so frustrating,

so i went to the place where i bought my macbook pro, and i asked if i could exchange my charger with a new or refurbished one,

and they said NO because its not the actual charger that is broken or malfunctioning, its just the exterior (chord) bit that is broken, so its not included in the warranty.

and they said it cost 90 dollars for a new charger.....

this is what it looks like, and i cannot understand how my warranty and apple care does not cover for the charger...