Interesting thread...
Personally regardless of "he said he would ship next day"...you should of waited abit before a dispute claim. Simple email / call to him saying "hey what happened" would of sufficed.
I sent back an amp and they received it on the 2nd. Over a weeks time I sent messages to them asking the status (nice emails...no WTF ones either) and they didnt answer a single one. I then filed a dispute. Got to have patience man...give the buyer some time regardless of the "agreement". The buyer very well may have told you Tuesday, but you just handled it wrong. Should of tried contacting him a day or two to figure out what was up.
On the other hand, I wont call you a "douche" since I wasnt there or in any part of the transaction. Just think there was a communication breakdown....hey! isnt that a song????