I'm with Virgin and the only advice they give is to change my phone number. I don't want to do that and in any case they would soon find the new number.
01234 567890 can be a real number - it would be in the Bedford area. I doubt it is used though, and it you do a Google search on that number you will see that lots of characters use that number for carrying out so called surveys, or about claiming for missold payment protection insurance, or other similar stupid things. This week I've had a similar type of one of these calls on a daily basis.
Although this has to be one of the biggest irritations in modern life, I doubt whether the government is likely to have it very high on their list of priorities.