As you have removed clear warnings that GHS no longer mine bitcoins from your site I am now able to report you to:
http://www.actionfraud.police.uk/and
http://www.fca.org.uk/The reason for these reports is because you are mis-selling GHS to investors without clear warnings that there will be no return on investment.
No need to argue your point anymore. The complaint has already been made.
I don't use CEX anymore and maybe I'm missing something, but I don't think you can report mis-selling if nothing was mis-sold to you, as you're aware of how the site works. If you're still able to turn-on the mining option and mine (at a loss), then you can hardly say it's miss-selling. It would be the case if they somehow suggested it is profitable and/or encourage you to buy inactive Ghs.
Also, how exactly have you made a complaint directly to FCA, if FCA suggests making complains to FOS?
http://www.fca.org.uk/consumers/complaints-and-compensationEdit: CEX should definitely remove the pool speed info from their homepage, as it's indeed misleading. Since it's inactive, it should either say 'zero PH/s' or 'potential pool speed' etc. But it's probably best just to remove it.