This script is written to use SFTP, but your test at the bottom shows that they don't have SFTP setup or it's on a different port than 22.

I'm betting they want standard FTP. Try using the ftp command to get to the host or telnet to port 21. If you get a response, then they are using standard FTP.

It looks like you'll have to rewrite your script to use FTP, but I would confirm that is the case before doing anything.