Bottom line is the guy doesn't have money to pay for your parts. Period. Seen this a million times before. As another member said classic "Rob Peter to pay Paul" If he had the money, you would have your parts. That is why it is always "something". Everyone else is messing up. It is Racelogic's fault, or Speedhuts, or whatever other BS he can concoct to buy time.
Busy isn't an excuse. It would take less than a couple hours to order all of the ordered parts, or refund the money, if he had the cash.