A common problem since google etc will often find older web pages with 084/087 numbers. Even when these have been superceded. Or 084/087 numbers left on web pages because webmasters have been unaware or not bothered to keep info up to date.

Example with 0870 number:
http://www.energynetworks.org/info/faqs/who-is-my-network-operator.html

I've reported a similar problem to Santander bank which still shows 084 numbers on some pages for contact in case of problems. When I complained all I got was a statement that they had switched to 0800 contact numbers. They don't even properly acknowledge the problme and even when they did, they said it would be fixed. A year on and it hasn't been.

allegro wrote on Aug 8^th, 2017 at 8:12am:

Good Morning allegro

It doesn't get much better here, or here

However this link which gives the same number out, suggest's it's run by National Grid, and any complaints appear to be dealt with by Cadent

Looks like Cadent are the ones to start with, to see if an alternative has been set up, the 0370 equivalent does not work.

On a seperate note, several of the pages visited give out a range of 0845 numbers for the Electricity Suppliers, have they all changed? 

I have contacted the Fair Telecoms Campaign with regards to this. 

Good Evening Ian01

Have no fear I have pointed out the "error" of their way's.. 

In this modern age with a large number of people using only a mobile phone, the costs to call that number are prohibitive, and for what gain?  As you have pointed out, very little! 

I have as yet still received no reply from Xoserve, despite the original contact being made over a week ago, this I why I have suggested Fair Telecom's maybe interested to take this on.