Hi TildaHalliwell,
Thank you for reaching out to us in our community and welcome here and to Virgin Media, sorry to hear you have been facing issues trying to get an earlier Install date, I was able to find you with the details we have for you and it looks like to were able to reschedule, if this isn't the case and you still need help please do not hesitate to reach back out.
Once your account is up and running, don't forget to set up an Online Account so you can manage your account, view bills and make some minor changes.
Regards
Paul.