unfortunately, it seems like you got beat with your purchase of used memory. just to be certain, try booting with a SINGLE stick of the ram in question. if one stick will boot and the other wont, that's the bad module. if both don't boot, then it IS possible both sticks are bad. theres a 3rd possibility, not a good one, but its possible since you bought used ram that its not actually the ram that was advertised. there are some online sellers (via e-bay and other sites) that sometimes advertise "g.skill memory" but ship Samsung sticks with g.skill packaging/heatspreaders as an example. either way, I would recommend trying to RMA the memory, it seems the whole "new" kit is a dud.
fortunately, most of g.skill's ram is warrantied for life so u may be able to RMA the defective kit for a brand new kit.