I had the same experience last May 2005. I bought new magwheels from Rota direct from their factory and was having them mounted in a shop near Kanlaon. They were recomended because they were doing wheel mounting using machines. However, the operators were careless and they ended up scratching the rims of both the new and old mags i had. Had a big fight with them, the owner told me it was not the fault of their company and i had to settle things with the employee.
But aside from that, i found out that they failed to tighten the lugnuts correctly. I was driving along commonwealth when i heard a clacking sound on my front wheel. I even stopped at Toyota commonwealth for them to check the wheels. When they found nothing wrong, I went home and tried to see what could be causing the sound. As a last resort, I tried turning the lugnuts. Sure enough, they were loose enough to be removed by hand. Always have your lug nuts attach using a wrench rather than use a machine.