Adele fans around the country are demanding answers after being left empty-handed by Ticketek and Ticketmaster websites which buckled under "phenomenal" demand.

Customers trying to secure tickets to the 10-time Grammy winner's first Australian tour on Monday morning reported being left hanging by engaged customer service lines and websites which continually crashed.

The British singer's Melbourne show sold-out in just over 30 minutes on Monday morning, at the rate of around 2000 tickets per minute. A second show was announced by the singer to meet "phenomenal demand" one hour later.

But aggrieved fans still struggled to secure seats, venting their disappointment and frustration after the ticketing agencies' websites and phone lines failed to keep up with demand.