Get right back on the horn with them and say you took it off. Since it's just a plug in component, you can just remove it if they want to see.
You can also download the programming from it into a Tuneboy or TuneECU program and just upload it to the bike's ECM, that way they won't know about it.
If the TuneECU upload works you can just sell the PCIII here on the site.
Those are just suggestions to your dilemma, I don't live in the UK so I don't know what you can get away with. Hope you figure out a solution soon.