Encountered the same situation, window wind down but stuck and cannot wind up.
For my case, the motor was working, as i can hear the motor when i pulled the switch. The window seem to be unable to come up as some was stuck and preventing it from doing so.
I tried the layman approach of troubleshooting: knocking around the door , pulling the slit of the door where the window retracts into slightly apart, etc.
After some trial and error, the window wind up! Saved some money for repairs.
It recurred once more so far and my trial and method worked once again. Didn't send it for repairs as it was the rear right passenger window and seldom wound down.
Maybe you can trial and error to wind it up first before sending it for repair.