A lot of people are conflict adverse and picking up the phone to talk to somebody about how they haven't held up their end of a transaction isn't fun to start with.
The customer service problem here isn't that they didn't answer his call, it's that he has to call to complete an order which clearly failed to execute through no fault of his own.
Caveat Emptor - Do business with vendors who charge your credit card when they ship and not when you order.