Sometimes you can work around it and just use the native VPN or TunnelBlick. Did this at a previous corporate gig where the software they used wasn't even available for macs. Gotta be lucky though. By this I mean that usually VPN software just has a default config for some VPN protocol, and if you can find out what that is, you might be able to input the same config and credentials into the TunnelBlick or network settings
