Negligence and bad customer service

We received the first quote for our Ford Ranger, for just over R7000 and we gave the go ahead to have the over fueling and black smoking fixed. Then we got a call to say that the injectors where generic and it would cost R2000 more to have that fixed, bringing the quote to R9757 on 30 April. On 4 May we phoned to follow up on the progress and where told that the bakkie where ready for collection and that Bosch closes at 3:00 on Fridays. I took half day's leave and rushed from work to pick up my husband and make it to Randburg as we had to borrow a car for the week our bakkie was at Bosch. When we arrived at the office and settled the account in cash. We where told that we had to wait a couple of minutes, as the bakkie is still being washed. When we eventually got the bakkie, my husband drove it to a garage near us as I had to put in petrol in the borrowed car. I traded cars with him as he wanted to see if the bakkie still smokes excessively. I drove about 2km and told him it feels like the bakkie has no power what so ever. He said he noticed that and that the bakkie is still smoking. (Everything we took the bakkie in for, is still wrong, then add some more) We gave the parents their car back and dad and hubby had a look at the bakkie. Bosch didn't put back the nuts on our engine!! Hubby took the matter up with Kobie, who told him there is not much he can do about the matter, as their computers where ****** over the weekend. Hubby took the matter further with Bosch. Kobie, the manager and the mechanic was charged with neglect. As compensation they said they will fix the bakkie, or refund us R500... R500 is an insult and I do not trust them near my bakkie again . How do they expect me to fix a R9000 mess with R500?