[Babul]

i suspect the return will abort your subroutine before you get the reward, and maybe not even the text will showup, coz its behind the return...
try that concept for just that case, if it works, modify the remaining too

Code:

case 0:
{
if(PlayerInfo[playerid][Deathstreak] == 2)
{
	SendClientMessage(playerid, COLOR_WHITE, "You have been given some brass knuckles as a death reward.");
	PlayerInfo[playerid][Deathstreak] = 0;
	return GivePlayerWeapon(playerid, 1, 1);
}