Brake Problem

I have a 1996 Hyundai Accent 4dr 1.5lt gs petrol. Had a problem with excessive handbrake travel, took it to a national brake/ tyre Co to sort it out, they advised the rear cylinders had leaked and required new shoes,also the dums were heavily grooved, he replaced cylinders and shoes but couldn't get drums, so he cleaned them up with a drill and flap wheel to remove the grooving, i was told they were within tolerance. I paid my money off i went, then i noticed a drumming sound from back, was told just bedding in, 2wks latter had no handbrake at all, it felt like shoes were not bitting into the drums, took it back, and they re adjusted them up and told me they were ok, i took the car round the block and noticed a smell. and smke pooring out the rear inside wheel, the drum was red hot, it cooked the fluid and nearly set my car on fire, i took it straight back and left it with them. " this is where my problem starts.. They phoned me 3hrs latter and told me to come straight down , as they could not figure it out. Car jacked up with no rear wheels on,the drums rotate no problem, then when the brake pedal is pressed , they do not release, he cannot turn the drum round, until, this is the weird thing he taps it with a hammer, and hey presto spins perfectly, same on other side, if the drums are removed, and the pedal is depressed slowly , you can see them expand and contract perfectly, They have come up with some solutions ?

1) Rear flex hoses may be colapsed in side, ? 2) The brake servo / master cylinder is faulty ? ( expensive ) Any help would be greatly appreciated Ditch.