Well, if they're stuck on and you drive round the block, you just risk getting them too hot and warping something or boiling fluid.
When mine stick on, they free straight away. Sounds as though either the cable has seized or the arm on the caliper.
If the cable is seized, new cable.
First of all, I'd take the rear wheels off and check the calipers and whether you can free them by unhoking the cable.
When applying the brake the caliper does not move, and i believe it should.
Does this mean the caliper has siezed?
and need stripping down?
Cheers Steve
Your not having much luck with this buddy are you! You get any warranty?
I would take it for a gentle drive to free them off.