BAD SERVICE, MISDIAGNOSED AND FRUITLESS EXPENDITURE ON THE ROLLBACK TRUCK

My truck was booked in at Westvaal Truck Service Centre and has been there for more than 2 months. The truck problem was not starting and they said it has lost memory. After some time they came back with quote of 4000. When I give them authority to do the job, after few weeks of following up with them then they made a mistake the problem is huge it need 25000, which I also agree. After few months the said the truck is ready to operate they have tested it. But immediately while still in Polokwane I realised the deck is not operating, I went back and they did something and left it operating but the problem is the operation couldn't be stopped loading/offloading memory but they said it will operate. Back home that night the truck couldn't load vehicle as the deck was not operating . I called them and they they send their machanic who did nothing and later requested the truck to be towed back to them on my expense. It was again dropped at them and they took their time to diagnose the problem, then they again charged me 27000 which I paid. Back again after collecting the truck it couldn't load any vehicle because it has no power and couldn't even get to nearest point. They send an electrician who confirmed that he told them about the problem and they told him that they can't order the part as the truck is needed to operate. The truck is now sitting at my yard and they requesting that I for the third time now consecutively should bring it back "Hi you can bring the truck back for proper diagnose as to see this an be another problem", but why the problem was not seen while it was diagnosed first because the truck never worked and it was at their workshop long enough to diagnose it properly as he say. Now I want to know who carries the tow expense because the truck never worked he said management agreed the client should do. MY PROBLEM IS THIS TRUCK ALREADY HAS TAKEN 25+27 thousands AND OUT OF THAT HE WAS GIVEN ENOUGH TIME TO FIND THE PROBLEM AND EVERYTIME HE GAVE US ASSURITY THAT HE TESTED IT IT WORKS PERFECTLY BUT SAME DAY OF COLLECTION IT CANT DO A SINGLE TRIP OR EVEN A 200 METER TRIP BACK HOME. This they can't explain why, the money I have been paying just went down the drain because the truck never operate straight from this workshop. I want to know what was their reason for getting to the first conclusion of the 1st and 2nd problem they said they found, AND how many bookings must happen and how much should I pay them for the truck to function again straight from them, looks like it only function in their yard only and back home it doesn't want to. SO WHAT IS IT THAT MAKE THAT TO HAPPEN. I can't keep on paying or something that is not working to bring back the money, the 2nd invoice doesn't he couldn't even tell me how did he get to 27000