Allowed memory size in PHPExcel

I need to upload xls files and their read for insertion into db, if a file reaches megabytes always the message is returned to me:

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 262144 bytes) in

Code for reading xls

require('library/php-excel-reader/excel_reader2.php');
require('library/SpreadsheetReader.php');

$inputFileName = '/home/uploads/'.$nome_arquivo;
$header = 'Conta';


    $inputFileType = PHPExcel_IOFactory::identify($inputFileName);
    $objReader = PHPExcel_IOFactory::createReader($inputFileType);
    $objReader->setReadDataOnly(true);
    $objPHPExcel = $objReader->load($inputFileName);
    //Get worksheet and built array with first row as header
    $objWorksheet = $objPHPExcel->getActiveSheet();
    //excel with first row header, use header as key
    if($header){
        $highestRow = $objWorksheet->getHighestRow();
        $highestColumn = $objWorksheet->getHighestColumn();
        $headingsArray = $objWorksheet->rangeToArray('A1:'.$highestColumn.'1',null, true, true, true);
        $headingsArray = $headingsArray[1];
        $r = -1;
        $namedDataArray = array();
        for ($row = 2; $row <= $highestRow; ++$row) {
            $dataRow = $objWorksheet->rangeToArray('A'.$row.':'.$highestColumn.$row,null, true, true, true);
            if ((isset($dataRow[$row]['A'])) && ($dataRow[$row]['A'] > '')) {
                ++$r;
                foreach($headingsArray as $columnKey => $columnHeading) {
                    $namedDataArray[$r][$columnHeading] = $dataRow[$row][$columnKey];
                }
            }
        }
    }
    else{
        //excel sheet with no header
        $namedDataArray = $objWorksheet->toArray(null,true,true,true);
    } 

The error always returns on the line:

$namedDataArray[$r][$columnHeading] = $dataRow[$row][$columnKey];

that is within foreach .

I've added it at the beginning of the file:

set_time_limit(0); ini_set('memory_limit', '2024M');

Unsuccessful