Calipers

Had 4 New bBrakes Installed On My 2001 Sonata 1 Month Ago. On My Way Home I Smelled Burning From Rear Drivers Side Brake. Went back To Shop And They Installed New Caliper.
Next Day I Smell Burning From Rear Passenger Side Brake? How Likely Is It That The Calipers Would Stick After A Visit To A Shop?
Is There Something The Shop Could be Doing To Cause This? Thanks.