I booked a one-way award ticket on UA to Israel for Succos. A much better option opened up out of a different gateway so I called UA, paid the change fee and was all set. The agent for some reason didn't know she couldn't book me a stop-over on a o/w ticket and did it for me. An hour later I realized that Shabbos/Yom Kippur started an hour earlier in NJ than I thought and now my afternoon flight to EWR is cutting it way too close for my comfort to make it in time for Shabbos. I called UA to try and change that leg of my flight and they said since the agent booked an "unauthorized" ticket that it could not be changed - even for a fee. I played HUCA of course and the next agent I got told me that any change to this ticket would completely invalidate the entire ticket. Evidently there were notes in the record from the previous agent. The agent knew I called before and was very mean about it. I don't think they would let me change the ticket even if UA made a time change to the flight....Any advice would be GREATLY appreciated.