Please ensure that the pqgrid.min.js file is loaded before and not after the below lines of code. If it's loaded after theses lines, it would reset the regional strings back to English.
$.extend($.paramquery.pqGrid.prototype.options, $.paramquery.pqGrid.regional[locale]);
$.extend($.paramquery.pqPager.prototype.options, $.paramquery.pqPager.regional[locale]);
Please share a reduced test case (exclude other unrelated code and scripts ) or a jsfiddle if still facing issues.