I referred a friend earlier this year who took up the offer and had VM installed (TV and broadband) using the refer a friend link I created.
However Aklamio (claim request 261782) have advised as follows:
Unfortunately, I can not find any indication that the Virgin Media agent, on the phone, has applied your referral code correctly to your Aklamio user accounts. This means that rewards that weren't automatically recorded cannot lead to further investigations. I can only direct you to Virgin Media, hope they can offer you a solution.