Klintay, theres always going to be a "that guy". If you tested the miners and they work send them back to him and be done with it.
If he tries to mess with them then that will void the warranty. His miners didnt reach the 550gh he claims. You proved otherwise in a variable controlled environment.

Cactipsi, make sure your power supply is powerful enough to run the miners at 100%. If you bought a cheap one than your problem isnt with eyeboot.
It could also be with the circuits in your house not having enough amperage to give out.

Go test these before you come crying back again