Thank you for contacting support.
Unfortunately, Virgin Mobile is not one of the supported networks as it doesn't support the 'Call forwarding' feature which allows the HulloMail Voicemail service to work, basically the network is unable to forward calls to us.
I'm really sorry to say, but at this stage your only options are:
1. Move again to another Network that does support call forwarding
2. Cancel the HulloMail service - If you wish to do this, please send us an email at firstname.lastname@example.org with your number so that i can provide you the correct instructions in order to do so.