"Our registration was renewed recently but this has not been reflected on the ICO registry yet," a spokesperson said.
Didn't you follow that up with a query to the ICO? Indeed, didn't you ask the ICO about any of the other interesting aspects of the app? Go on, you know you want to.
Maybe there's also scope for some questions next time it's his turn in the barrel in the HoC. A nice general question about privacy of apps in general followed up by asking how that applies to his own. Are there any MPs with sufficient technical knowledge to make a decent job of it?