Oscar, I think we can all understand that the magnitude of this group buy caused it to go off the rails. People got excited with another cut card group buy after there hadn't been one in quite a while. You got excited because, from personal experience, it is kind of exciting running a group buy. Nothing that's really your fault there - it just escalated really quickly.
That said, I think the biggest complaint that you have heard throughout this thread is the fact that you posted things about the status of the order (for months) and about delivering items to the post office that turned out to be untrue. Just be up front with everyone, and people will (typically) be incredibly understanding. But once one post turns out to be proven false, then another, and another, etc. That's when it really got under a lot of people's skin.