2002 sonata brakes and rotors

i recently purchased a used 2002 sonata with approx 55,000 miles on it.
the back and front brake pads and back rotors needed to be replaced
within the first 200 miles that i drove the car. the shady dealership
that i purchased the car from did (very reluctantly) pay for most of
the work done. now, less than 3000 miles later, the check engine lite
is on and i'm told that the back rotors are shot again. does this
problem sound familiar? should i try to get rid of the car? i told
the mechanic not to replace the rotors and i'm getting a second
opinion but is this characteristic of this car or what? any advice is
appreciated.

 

What was wrong with the rear rotors to begin with, how did the dealer
rectify the issue, and what is wrong with them now?

 

the brake pad on the rear right tire was worn down to the point the car
sounded like an airplane cause it was metal on metal, and it even
smelled like synthetic burning from all the friction. the same EXACT
damn thing is happening again now, only a month and a half after i had
the entire freaking brake system replaced. im thinking the brake is
locked or something causing it to be permanently using the brake and
thus wearing it down. i dont know how else to explain a band new brake
pad being TOTALLY used up to the point there is only metal of the disc
left after 2000 miles of driving when they usually last 40 thou easily.
i really think im going to sue the dealership. they also but 2 quarts
too many in the engine. the engine could be messed up now. i cant
believe this bullshit, excuse my language but this is insane. anyone
know what could be causing this? i think ill have to sell the car
cause no one knows whats wrong and i cant put out 200 dollars every
month to replace brakes and rotars....which are being carved into right
now cause there is no pad left. please, someone help me. im a college
student, i dont have any money. i cant deal with this.