Subaru Legacy Key Fob/remote wont pair

Hey, so I just got a Subaru Legacy L sedan (2003). I got a remote off of ebay
(the one with the orange and blue buttons), and looked up how to pair it.
When I go through the steps, make the car chirp once, then open/close the
driver door, I proceed to click a button on the remote, which should prompt
the car to chirp twice; it doesn't. The remote's red light often blinks red, but
more often stays red until I fiddle with it. After that I take the key out and it
chirps three times, ending the pairing process. The remote doesn't
lock/unlock the car. I tried changing the battery, same deal, same red light,
same no pairing. One time I held the lock button on the remote and, for
some reason, it made the panic alarm go off. Around that time, it locked the
car too, but it never like actually does the whole locking and unlocking thing.
Please help.