Don't worry about it, they're very professional and will make sure you get the tickets one way or another. I hadn't received my ticket for yesterday's St Petersburg show 3 days before the concert, so I e-mailed them and they responded within hours and made sure an e-ticket was sent to me.
If you have any concerns, don't be afraid to contact them. Unusually for a ticket company, they're actually spot-on when it comes to liaising with customers. For those of you flying to places, and worried about being home when the ticket arrives, again - just write to Crowd Surge and tell them your concerns, they'll do everything necessary.