I've removed the 020 alternative and replaced it with "unknown". In the Other Information column I've put a link to this thread.
If you have followed that link, then see previous postings for the information and leads we've found thus far. If you can help with this, then please post here (or you can e-mail me
dave {at} saynoto0870 {dot} com
).
Such contribution can be anything and certainly doesn't have to include an alternative number. For example, the name and/or address of the office where calls to the 0844 number are dealt with might be a useful clue. I made a suggestion before as to where calls are answered (based on what I'd found) and if anyone knows any different or can confirm what I found, then let us know.