Check that the pogo pins in the cradle aren't damaged - this can happen if inserted and closed incorrectly.
I would look at cleaning the contacts on the buds too, just in case there is dirt on them preventing connection.
Plug a USB cable into a closed set of buds for 7 seconds it's like a soft reset.
Finally, press and hold your buds into the cradle for 7bseconds (except iconX and original buds (r170)). Device will go into pairing mode and connect to each other.
Failing that, go to a Samsung repair centre with your receipt if its in warranty as they may need exchanging. If its out of warranty then you may have to pay for one of the buds to be replaced.
Hope this helped!