How to read and validate csv input and the rows

public function execute()
{   
    $data = [];
    $file = $this->getRequest()->getFiles('refundcsv');
    print_r($file);//display the input file name 
    if (!isset($file)) 
    {
        throw new MagentoFrameworkExceptionLocalizedException(__('Invalid file upload attempt.'));
    }
    $data = $this->csv->getData($file); //throws error
    print_r($data);
    foreach ($csvData as $row => $data)
    {
      if ($row > 0)
      {
         print_r($row);
      }
    }
    die();
}

I want to read the csv input file and validate the rows. While executing the above code shows an error.

Warning: file_exists() expects parameter 1 to be a valid path, array given in vendor/magento/framework/File/Csv.php