Are VM/O2 data mining?

I recently purchased a new VM package (broadband getting installed in 2 days time), it included an O2 sim card in order for me to get the 500 Mb --> 1 Gbps download upgrade. My account in VM's website and contract documentation all state my correct forename.

Unfortunately, my O2 account, which I've activated and using the new SIM, shows an incorrect forename. I am aware that personal info needs to match between VM and O2 in order to benefit from the Volt/broadband speed increase, and so, I phoned O2. Unfortunately, they are insisting I send them 'suitable ID' documents e.g. marriage/Birth certificate. I told them all the info they had to set up my O2 account was provided by VM, thus, this 'mistake' did not come from me and so, they need to request the correct forename/info from VM. I reminded them that, crucially, I did not need to send that info to set up my new VM account, thus, they 100% do no need that from me...at this 'initial'/account setup time. But the call handler seemed adamant that I need to send this info in! She did 'create a ticket' so that someone else can look into this...no doubt sticking to the same line.

This 100% smells of data mining, and I will NOT - obviously - be supplying any more personal info than is needed to set up these accounts. I wonder how many people have needlessly/wrongly(!) sent in these crucial ID documents?

Can someone from VM let me know if my Volt benefits are going to be taken away? Additionally, can you contact O2 and get this sorted out?