Mitsubishi George - Bad Service and Extra Cost

Booked by Bakkie for a Major Service at Mitsubishi George, what should have taken half a day took 2 and Half Days. The Workshop broke of a bolt and blamed it on a previous person that supposedly stripped it, but no one else worked on this, timing belt was previously also changed by Mitsubishi George. The really sad thing about this is that I got charged an extra R2000.00 for this, with no notification of any extra cost. Mitsubishi only contacted me to say that my bakkie won't be done in time, but no mention of any extra cost. And I had no choice but to pay up for this !! otherwise I could not get my bakkie back. I own my own business and can't afford to sit without my bakkie for 2 days extra. I have the faulty bolt, it looks like someone tried to loosen it with an incorrect size tool and stripped it, why should I pay for an workshop error. Very unhappy, I always have my bakkie serviced at Mitsubishi but feel really annoyed with the treatment I got from the staff and the service of my vehicle.