Earlier quoted context omitted.
There are a number of reasons this could have happened: 1. You left before any of your stock vested. Assuming a standard four year vesting schedule and a one year cliff, this makes complete sense. (Although you are saying that you paid for your options, so this likely isn't the case here). 2. The company got shut down, its assets liquidated, and the founders and a select group of employees went to work for Google. Th…
'Paid for my options before leaving the company.' means #1 is irrelevant. Chances are there was some issue with preferred vs common stock.
If the OP left after staying less than a year, they most likely didn't vest anything.