The situation puts three main possibilities on the table:
1. The switch is faulty
2. You have connected your circuit between the two throws
3. Your circuit is non-functonal for whatever reason
The first thing I would do is, as SL4P said, check the pins with a multimeter in continuity mode to figure out the pinout and check if the swhitch is good or faulty.
There should be a combination of two pins that doesn't have continuity in any of the two positions of the switch(since these ate the two throws) and any other combination would have continuity in one of the two positions of the switch.
This will check the veracity of the first two possibilities, and if that's the case, the switch it's not the colprit
I hope I have been helpful
