your the type of customer dealerships hate.

"you replaced my brake light and now my engine has run out of oil. its your fault fix it."

what is happening is your rear brake pads are at about 1.25 mm. at 1.2 mm is when they are supposed to be replaced, and when the squeeler will come into full contact with the rotor.

so quit trying to scapegoat the dealership and deal with the fact that a heavy wear item has done exactly that.