Lets just say that the brakes were bled correctly, and shoes were not centred. I think even if the shoes are not centred, after application of brakes quite a few times the shoes get to adjust themselves against the drums all by themselves to get centred eventually (if I am not mistaken).
Having air in system seems to be the real trouble here.
B/w $487.03 is a big price to pay for a brake job (especially when you can get it done here in this part of the world for Rs. 200-500, lowest being Multan's rate and upper being ISD rate) but then if it keeps you/your family & Billo safe, its a small amount of money to pay for a lesson well learnt for future.