ive got a rear disc conversion on my fiesta and i think the rear caliper may have siezed but im unsure, on the back of the disc the pad is permantly touching the disc in only one place, its not completly flat against the disc and the caliper pistons seem to be at an angle. now has it just got stuck and need releasing or has it siezed? i need to know asap cause ive allready put a wanted ad up and im trawling ebay and found a few new and reconditioned one

please help asap thanks in advance!