One time I had a non-rev ticket to fly from SJU to MIA on AA and the flight was full, so I asked the gate agent for a jumpseat and she said that it wasn't possible because the plane was overweight. I asked her to talk to the captain but she said that the captain had nothing to say about it. So, I had to wait for the next available flight.
AA has some interesting jumpseat rules, including the role/power of gate agents. That being said, the PIC always has something to say about it, and you should forward such issues to your jumpseat coordinator so he/she can attempt to fix the problem so the next SJU non-rev pilot isn't left behind.
