They're owned by one company, in practice there's very little operational integration. Which means that they use different IT systems, different processes, and whilst their agents happily cross sell, the companies maintain that if you're cancelling or have problems then they're legally separate. In one respect they clearly are merging - VM customer service has always been appalling, but O2 used to be reasonable. Since the merger, it's been all downhill for O2 customer service, obviously the plan is to use the same poor quality offshore support model to achieve the same universal standard of ineptitude that VM believe is adequate.
But coming back to the point, the forum staff here are Virgin Media employees, they have access to some of VM's systems, none of the O2 systems. If O2 have failed to process a cancellation request within the cooling off period, that's a breach of the relevant UK Consumer Contracts law. You can try again with O2 - it might just be that they are slow to process the cancellation instruction and you'll get a credit in due course. If they haven't cancelled it, or give you ANY difficulty, then you need to raise a formal complaint with them, asking for the matter to be resolved and payment of a modest compensation payment of say £50. If they don't comply with that then you contact CISAS to see how you can escalate the complaint to them.
