UKPassats

Ok so not having a good time with this car had it less than a week's. Car had been ok break issue wise was driving stop got out came back after 5 mins went to drive rear drivers side breaks stuck . Jacked it up unplugged the electronic plug plus it back in to see if it would reset tried to reset it on the laptop not having it. I was far from home so I took the electronic bit off the break and wound out the caliper.
My question is it like to be the caliper or just the electronic bit? It was making a noise like a long winding noise when got out went it Jammed