Roadnav.co.za disgusting service

I recently purchased a vehicle android head unit from Jason. He insisted I use his installer and I did. paid for the job. Now because I was not there and it was only my wife, his installer did a terrible job, wires hanging, dashboard covers left with huge gaps, previously working reverse camera now no longer working. My wife showed this to Jason who refused to acknowledge. Now when I'm trying to call both him and his installer they ignoring my calls. Jason from Roadnav is a ***** and unprofessional person. I will never recommend him or his services.