Alberts Car Stereo Joondalup

I went here to get my stereo installed. They quoted me $750 for 2 subs, speakers, 2 amps and a head unit. I took my car in and when I received it back there was a buzz in my stereo. I could hear the car accelerating through my stereo. Upon bringing this to their attention, they informed me that it was the amp I was using. They had broken my seat belt during the process and had not bothered to fix it. Under a week later the speakers were cutting in and out until the point where only the subs would work. I was told by them that it was the amps fault, so I purchased a new amp. They charged me $250 to fix their screw up when all they did was put on a new earth cable as the last one they put in was too thin. After connecting up the new amp there is still the buzz in my stereo and now they are telling me that it's the head unit. They scratched all the interior in my car, obviously using a screwdriver to prang the covers off. I refuse to take my car back as they are completely useless. Not to mention I took my car in on my lunch break to see if they could see what was wrong quickly so I knew what to fix. One of their so called specialists spent 45 minutes taking the cover off my engine to then tell me he didn't know what he was doing, and didn't know what he was looking for, and he is only working there because it;s better than school. Basically if you care for your car and equipment, do not go here! Alberts in Midland has much better service and are much more reasonable.