VM's responses on this sort of request are random, and often make no sense, but the most common reply is that they won't do anything about old cable installations unless they are causing a health and safety problem. If you think that is so in your case, post up some photos to illustrate the issue causing a danger.
As a general point, it is best to leave the cable and box intact in case you, or anyone else, ever wants VM services again at the property. It is easy enough to do a DIY tidy up of the cable and external boxes can easily be obtained to enclose the ends of the cable should VM turn down a request for a remedy to the issue.