.Net Assembly - Filename which contains text within "[ ]" is not downloaded

Filename of format testfile[dev].xlsx is not downloaded

TransferOperationResult tor= session.GetFiles(sftppath, localpath);
if (!tor.IsSuccess)
{
Console.log("File Copied");
}

tor.Is success returns true.But file is not copied to local path

Please read documentation:
https://winscp.net/eng/docs/library_wildcard