The idea of a bond is for the company who have invested in training you want something back, i.e. a bit of commitment.
You have 2 choices, say no, or if you want to leave during the bond period pay up!
I have been bonded, most I have completed, 1 I left before the bond had expired and paid back what I owed, it goes down pro rato over a set period, it also didn't give me a black mark against my name, after all aviation is a small world, and breaking a bond by running away may well follow you as it's highly unlikely they will give you a good reference when looking for another job.
