problème avec getPage

<?php
/**
 * @var modX $modx
 */
 
// Paramètres communs à tous les départements
$parametres = array(
    'element' => 'getResources',
    'elementClass' => 'modSnippet',
    'parents' => $modx->resource->get('id'),
    'depth' => 2,
    'limit' => 6,
    'pageVarKey' => 'page',
    'includeTVs' => 1,
    'includeContent' => 1,
    'includeTVList' => 'ma_tv,tarif,ref,tel,departement',
    'tpl' => 'article',
    'processTVs' => 1,
  
    'pageLastTpl' => '<li class=\"control\"><a[[+title]] href="[[+href]]">Dernière page</a></li>',
    'pageFirstTpl' => '<li class=\"control\"><a[[+title]] href="[[+href]]">Première page</a></li>',
);
 
// Switch selon le département choisi
switch ($_POST['departement']) {
    case 'ardeche':
        // on ajoute les paramètres spécifiques au département
        $parametres = array_merge($parametres, array(
            'tvFilters' => 'departement==Ardeche',
            'resources' => '-12,-13',
        ));
        // on execute le snippet
        return $modx->runSnippet('getPage', $parametres);
        break;
 
    case 'drome':
        $parametres = array_merge($parametres, array(
	  'parents' => $modx->resource->get('id'),
            'tvFilters' => 'departement==Drome',
            'resources' => '-12,-13',
	  'parents' => '31',
        ));
        return $modx->runSnippet('getPage', $parametres);
        break;
  
   case 'isere':
        $parametres = array_merge($parametres, array(
            'tvFilters' => 'departement==Isere',
            'resources' => '-12,-13',
        ));
        return $modx->runSnippet('getPage', $parametres);
        break;
  
  case 'rhone':
        $parametres = array_merge($parametres, array(
            'tvFilters' => 'departement==Rhone',
            'resources' => '-12,-13',
        ));
        return $modx->runSnippet('getPage', $parametres);
        break;
 
 
    default:
          return $modx->runSnippet('getPage', $parametres);
        break;
}
 
return 'Normalement on ne doit jamais voir ce message, sinon une erreur s\'est glissée dans le code!';