Virgin continue to bill you as usual until your disconnection is complete. This helps to make sure your final month of service isn’t interrupted.
You will therefore probably see charges that go beyond your disconnection date, normally because your cancellation date takes effect mid billing cycle.
Once your services are fully disconnected VM recalculate what you’ve used and send an adjusted final bill detailing any credits you may have for the services you haven't used. They then refund those monies by cheque around 45 days after the account has closed.
Thank you for your post and welcome to the community.
I'm very sorry if you haven't been advised with regards to any left over credit.
As newapollo has advised, any left over credit would be refunded via cheque 45 days after disconnection.