Had my car serviced by a repable shop known by everyone in sydney, cost $280. Was happy with it, minus the fact when they took off my oil cap on block (top of my xr6 turbo), the cap broke in half. Half in one hand, other half fell in. Question is: should I have been charged the extra 120 (costing me 420 all up) to open it up and get the part out when it was their fault? What are your thoughts?