Williams Hunt Centurion are pathetic

I bought a 2017 Isuzu 2.5 X Rider double cab from my that bought it new in 2017. When i bought the Bakkie it had 36k kilos on it ans was still under warranty. The bakkie went for all the services with Isuzu as its still under Warranty. My last service it went to Williams Hunt Centurion on 76k and its standing on 83k odd kilos. I phoned them andbtold them that my car stuggles to go into first gear and that there are a noise when i pulled away. The guy said they did not work on my gearbox and diff so i must bring the car in on Friday as this was Tuesday and they are to busy that week. On Wednesday afternoon my bakkie broke and th AA came and they booked it at Centurion GM where bakkie was booked in. On Friday i phoned and the service advisor said its the diff they sent it to warranty and he said it full of water the diff. So i said how did they check the oil then on the service as they were supposed to do. A week later after i phoned 7 times and i sent one of my workers there the workshop manager phoned me back and said the diff is broken and there are dust in the diff the Warranty will not cover that as there are n small dent on the cover under diesel tank end that causes the breather pupe to broke. So i went there and the bakkie was still on the lift with my diff open. The oil was in a container under the bakkie so that manager thought i don't know anything about cars and tried to spin me alot of ****. First there was almost no oil in the diff. I realized i sent my bakkie for Dekra 1000 point inspection test on 36k kilos where they checked everything and sent report with fotos so i shaw that tha small dent was on the cover and that the bakkie had to drive 45k kilos and Isuzu never checked my diff oil if thats the problem that the manager tells me. So i asked can i please get my service sheet that they show that the service was done and all oils were checked no the manager is full off stories. I need that sheet as i will be taking it to Isuzu SA and the Ombudsman as i know they messed up and now want me to pay 22k to fixed my bakkie. And also my bakkie is used for my word so they will pay me for income lost also. The bakkie got 83k kilos on and i still drive with my original tyres on the bakkie i dont overwork my car now this manager thinksp he can bull**** me and tell me stories i got all my voice recordings where he think im stupid and the pics from Dekra to proof they charge for work and don't do it. I will never buy a Isuzu again