I've spoken with Customer Services this morning and been advised this time that a case has been logged for the network investigation team. They will look into this and perform a disconnect and reconnect of my number.
Customer Services guy seemed to be honest in stating that he wouldn't be the one doing this himself but it would be done by the appropriate team. It was noted that it isn't a five minute job, but requires some time and that it can be done, a clean up of the number.
I really hope that this will resolve the issue. It was said that the network investigation team also see a lot more diagnostics so it may be that they find something else to be a problem. I feel a bit more assured at the moment that the task is in hand and that this will have been completed within three working days. That is what I was told so I'll keep an eye on things, see what happens and maybe call back later in the week if this either hasn't happened as it is supposed to, or the disconnect and reconnect hasn't worked.
Elsewhere on another forum, someone suggested I request a new number though I really don't want to do that. It'll create a lot more hassle than it may resolve.
