I called tech support about this a few weeks ago - I buy a bunch of packs, and one of them has only three items. It took pulling teeth, insisting that I wasn't lying about it - and finally CS gave me some coins after a week. Great, no problem. But then it's happened again to me, twice in the last day! And the last pack I opened had only ONE item.
I understand that there are bugs...what I don't understand is having to argue with CS about a real money transaction not delivering as promised.