Can't receive calls from SKY mobile

I recently transferred from SKY to virgin media. Between them they managed to cockup transferring my landline number. With the help of Daniel_Et it was eventually sorted out. That was on 8th Jan. I can now make and receive calls on that number. However I discovered last night that if someone phones me from a SKY mobile they are informed the number dialled does not exist. I can phone them and my number appears on their phone. They cannot phone me back.

I reached out to Daniel_Et but as yet he has not responded. To expedite matters I am putting this out there for comment and help.