I joined VM in February this year and had asked for the number to be ported from my previous ISP (BT).
This did not happen so I used the Message Us portal. Still nothing happened.
So I emailed a complaint. I got an automated text message to reply to which was eventually picked by a human being. They confirmed (by text) that I have raised this matter a couple of times so they will pass it onto to the relevant department to look into (this was on 17Apr).
Since then, it's been radio silence.
I noticed a charge from BT on my bank statement (long after leaving and joining Virgin Media) so got in touch with them, They advised that my new ISP had declined the request for taking over the number so the account remained active (and got charged to me by direct debit).
After reading some of the threads on the VM Community pages ,it appears to be a fairly common issue that the landline number porting fails when joining VM.
I hope this can be resolved asap as it's dragged on for more than 3 months and cost me a fair bit of money.