Removal of old VM cabling and wall boxes is a regular request. Forum staff here can pass the request to the area manager, and sometimes they in turn will send somebody to remove the cabling and kit, but as a general rule they don't. Once you've cancelled VM and the service has ended, the cable will have been disconnected at the cabinet, and since there's no enduring legal right for VM to leave their cables etc on your property without a complicated legal agreement (wayleave), you are at liberty to remove it all yourself, and there's no safety implications (a) because the cable should have been disconnected at the cabinet, and (b) even if they've not done that the voltages used for signal transmission are insignificant.
If you're unable (or unwilling as a matter of principle) to remove the cabling yourself, then you can stand on your legal rights and demand they remove it. But it might take a while and formal complaints, even escalation to adjudication if the area manager chooses to ignore the matter.
