Sold used item. not brand new.

I bought a music system, LG cash and next day when I assembled it only to find out that it was used. The entire system was not brand new, some speakers were dirty showing that were being on shelves. And the DVD player had a scratch on top of it, showing that it was from display. But I was informed that it was brand new from box. I never checked the system in their presence because I trusted them. I paid it cash on the spot, R7500. When I play DVD, it has scratches signaling that it had been played before.