This always happens with ticketmaster and popular concerts. It's a complete gamble whether you get through or not, waiting queues jump up and down and the vicious circle just keeps spinning. One thing to keep in mind though, is that Ziggo just isn't a huge place and demand is high.

I got 4 GAs for the 10th flawlessly but maybe I got lucky and switched to 10th right as they went on sale.

10th is now available.