The following agreement contains a clause that asserts that either
party may terminate the agreement "with a notice period of one month".
(See section 6.)

https://www.ripe.net/manage-ips-and-asns/resource-transfers-and-mergers/brokers/ebonyhorizon-4.pdf

Who should I talk to within RIPE NCC in order to request that this
contract be terminated?


Regards,
rfg



P.S.  For those of you who are unaware, there has recently been quite
a lot of activity, and also a good deal of press coverage relating to
Bitcanal, specifically:

    https://dyn.com/blog/shutting-down-the-bgp-hijack-factory/
    https://www.theregister.co.uk/2018/07/11/bgp_hijacker_booted_off_the_internets_backbone/
    https://krebsonsecurity.com/2018/07/notorious-hijack-factory-shunned-from-web/