My brake caliper got stuck together, the mechanic unstuck it and its stuck again Iv paid my money?

Hi, please help, my mechanic unstuck what he told me was a stuck togther brake caliper, he managed so he says to unstick it,however, he told me it would never stick again, the same thing has happend Im uming, as the car is driving like the brakes are on. Is it posible for it to stick again ? and if so, (as he has told me it is not), Iv paid my money to have it repaird, once, and now its been back again, and its still doing it ? so.... is he just pulling my chain... as I dont want to drive the car with my children in it...and Im (not) a mechanic, and know nothing aout cars. Many thanks mum of two, and a broken kia 4 x 4