Bully Tactics and poor service

A friend wanted to by my father in laws quad. He collected it from me and took it to Shimwells Yamaha, who after +- 3 weeks came back with a quote of R27 000 for repairs. My friend and I agreed not to go ahead with the repairs and he brought the quad back. On arriving with the quad, I noticed that the air box was missing. My friend contacted Shimwell Yamaha, Braam said he will look around for it. After a day or two nothing was found. Feeling responsible, my friend bought a new air box from Braam for R2500. On checking the quad further, I found that the electrical for the display had been removed and not replaced. On calling Braam, he admitted that they do not put things back together if the quote is not accepted. He also then said that the quad arrived with no air box, as it blew off while on the back of the trailer. He then said he checked the security cameras and can confirm that there was no air box. I know that there was an air box as I washed the quad two hours before my friend collected the quad. Braam was not prepared to refund the R2500 for the item lost at Shimwells or fix the state of the electrical. He was rude and used bully tactics to avoid taking responsibility.