If you are clever and brave, you can repair it yourself.
If the spring is broken, it almost always breaks at the end. With a little heat and pliers you can bend a new "hook" on the spring and reassemble it.
Now, if the spring is NOT broken, but it just doesn't want to retract, then you need to add a turn to the pulley. This is done by pulling out a foot or so of rope, making slack inside the recoil, and winding a turn around the pulley. (I often grind a smooth slot in the rim of the pulley to make this job easier.)
If it's a broken spring, be sure to have a manual nearby as you disassemble it for they can be tricky.
Jeff