I have received "Anything we can help you with?" phone calls many times from Virgin. Often the in-resort rep does this. They don't allow you to online check in with infants, this caused us a lot of stress last time. However, if you are organised, you should not have problems getting seats allocated. Set an alarm on your phone to remind you at 0800 when to do the allocation. I set mine in January for next years flight, its not rocket science.............
Oh yes, chill out a little. These 'problems' are a bit of overkill
If you have a ticket, you will get a seat.......