No news yet on when Virgin plan to launch The Africa Channel but I did seen that the EPG on Channel 828 was saying on October 1st - 'Coming Soon' until Sunday night (October 8th) - so we may not see this channel reappear until early next week.
UPDATED at 12.50pm on October 2nd:
Virgin have just posted the following on their own forums:
"The launch of The Africa Channel has been postponed until further notice. This was scheduled to go live today (Tuesday 2nd October) on channel number 828 for M+, L and XL customers.
We will update once a new date has been confirmed."