Shocking service

I took my mower to him about 2 weeks ago with specific problems out lined to him after waiting 2 weeks and paying R1009 for the repairs I brought my mower home and tried to use it it worked for all of 10 minutes until the same problems that I took it to for were still there when I took the mower back to him after seeing with his own eyes that the mower is not working he still try's to tell me that it is a operator fault the thing is that I am the main operator of this unit and I have been cutting lawn with petrol mowers for many years now and I think that I know what I am doing