FTP is an ugly protocol because it uses dynamic ports, which either needs a wide open firewall or specific configuration within the FTP clients. Also it sends login information in clear by default and the encrypted version FTPS produces even more problems with firewalls. These things together make firewall admins hate the protocol and they better deny requests to allow it for security reasons.
Apart from that you request for port 21,22 was wrong: While port 21 is the FTP control connection port 22 is for SSH and has nothing to do with FTP. But there is SFTP which is a file transfer on top of SSH, which is totally different from FTPS which is FTP with SSL enabled.
But, port 21 is not enough to get FTP through. With FTP active mode you also must allow any connections from the servers port 20 back to the client and with FTP passive mode you must allow connections from any ports on the client to any ports on the server. The firewall might have a FTP proxy or helper to work around this and to get more restrictive policies but the usage is limited and it usually does not work with FTPS so that passwords are transferred in plain text.
Maybe you get from this description why the FTP protocol is considered insecure and hated by firewall administrators. I would suggest that you move instead to SSH/SFTP (needs only port 22) or that you use WebDAV (works with default HTTP/HTTPS ports).
BTW, if you have security questions you might get better answers at security.stackexchange.com.