I had the same problems but after trying a few times I got my tickets. Unfortunately I wasn't able to buy the VIP package with tickets on the GA floor. Calling Ticketmaster hotline wasn't very helpful, they told me the VIP packages for the GA floor were probably already sold out. Not very likely at 10 am just after the presale started. I tried other german cities as well, same result, no VIP tickets on the GA floor, only seats.