Low Quality Products

Last month, I went to ITC Mangga Dua to repair my Playstation2 (PS2) because it can't work well.
I am sure that the problem is the optic has become weak and worn off. So I told the vendor to change the optic. But then he said that my PS2 is an old type, so it can't play a lot of games. He offered to trade in my PS2 plus 800.000 IDR with the new PS2 slim. I thought that the new PS2 could play all the game titles, so I agreed to do the trade in.
When I arrived at home with excitement, I tried to play my favourite game, Gundam. I was really shocked that the machine couldn't play it. Then I tried another game, Namco X Capcom. The same thing happened.
The next day I went back to Mangga Dua to tell the problem occured. The vendor agreed that the PS2 is broken and then he gave me the new one. I thought this would solve the problem.
That night something terrible happened, the new PS2 was broken. It couldn't be turned on. When That happened, I was getting frustated and confused...Is this because the new product's quality is low or did the vendor give me the broken PS2 intentionally?