If you are in the UK (a resident or citizen) and you get hit with a CID ban, I recommend reporting it to the regulator. I'd just send the courtesy email that you are doing it, when you do it.
If there is some sort of mediation, I would ask for details of every account that the rogue CID is attached to, the device, IP location, trades taken with that CID etc with of course personal identification kept private.
I noticed something in a few of these x cases that I think can only be resolved with regulator mediation.