plz help

My 1997 GS-T's engine is unusable anymore and the dealer i got the car from won't even tell me why. He told me it'll cost me $2500 to replace the engine for another used one. I know the dealer is trying to screw me and he is supposed to pay 50%.

:iamwithst

yes now that i think about it i am stupid and i've only driven the car for 15 days