What's wrong with the $args [2] not working

public function onCommand(CommandSender $sender, Command $cmd, $label, array $args){
$db = new DBManager();
if($cmd->getName() == "setar"){
if(!isset($args[0])){
$sender->sendMessage("§7[§9!§7] Use§8:§e /setar <jogador> <tag> <mensal/permanente>");
return true;
}

$player = $this->getServer()->getPlayer($args[0]);

if($player == null){
$sender->sendMessage("§7[§9!§7] O jogador {$args[0]} está offline!");
return true;
}

if($args[0] == $player->getName()){
if(isset($args[1])){
$all = implode(" ", $args);
$worte = explode(" ", $all);
unset($worte[0]);

$ptag = implode(" ", $worte);

if($ptag=="dark" || $ptag =="ender" || $ptag=="night" || $ptag=="whinter" || $ptag=="yt" || $ptag=="ytmirim"){
if(isset($args[2])){
if($args[2] == "semanal"){
$sender->sendMessage("TEST");
}
}else{
$sender->sendMessage("§7[§9!§7] Use§8:§e /setar <jogador> <tag> <mensal/permanente>");
}
}
}else{
$sender->sendMessage("§7[§9!§7] Use§8:§e /setar <jogador> <tag> <mensal/permanente>");
}
}
}
}