CODE EXAMPLE FOR PHP

Laravel Excel numbers formatted as text still appearing as number

I found a workaround by using setCellValueExplicit()
eg:

$sheet->setColumnFormat(array( //se formatea la columna a texto
    'C' => PHPExcel_Style_NumberFormat::FORMAT_TEXT,
    'I' => 'dd-mm-yyyy hh:mm'
));

$sheet->setCellValueExplicit('C10', $object->card_number, PHPExcel_Cell_DataType::TYPE_STRING);

Hope this helps ;)