Bad service which leads to my money problem

I bought a VW Amarok in April as a second hand unit. I drove it the first time to Durban that day and the cruise control was not working, the spare wheel unit was broken. The wheel was at the back of the van. I complaint they said I need to bring it so they can take a look at it. Went there they fix the cruise control only. This past December I went for holidays to Durban and the car took off the belt while driving and took it to VW Amanzimtoti for a fix. Only to find that the problem was with the alternator the bar which holds the pulley is bent and the unit is on a working condition. I paid almost R 5500 for a second hand unit to be installed. The car was with VW for the whole holidays. In January the license disc expire and went for a new one and didn't get it because the car needed to go for roadworthy first. They said I need to bring it back so for them to take it for roadworthy. I took it there and if failed because of front tyres and was promised new ones are going to be installed for me. They took new tyres from the other vehicle and put them on my car and took it for roadworthy than it passed after they put the old ones back. Now I need to drive with unsafe tyres.