New Fail2ban bypass bad config?

hello i have more than 2 weeks dealing to block this guy from my freepbx install, i try to block from iptables directly but no luck, fail2ban have it reinstalled and updated rules 3 times, including the freepbx integrated,

i have give a try to a method of limiting the time to make new connections on the 5060 5061 ports see here in red, i find this here iptables rate limiting | The VoIP-info Forum but all this is not working with him, the extrange thing i see is that whatever software or system he is using to brute force my server send a new port on every try.

is there any help or any other way to block him ?? my server is hosted in digitalocean