I'm from India. Purchased from a known seller in local PC parts market.Not sure where in the world you are, or how you purchased the RAM.
If I was in your shoes:
1) return as defective/not compatible since they can't even run at XMP speeds in a single stick installed configuration
2) look towards credit card return protection if seller won't take back
3) try to RMA to manufacturer
4) buy a new kit: RAM is pretty cheap. Sure, it stinks to have to shell out more, but it is not a lot more
5) try to sell ram you won't use off