Well, its a shame to lose a long-time customer, but he sounds like the sort of customer you don't really need. I'm guilty of being late picking up comics at my local shop, but I only have TMNT subscriptions, my total is usually under $20.00. They also have a working number for me. For all you knew he was dead, or in prison, or overseas, or god know's what.
Re: *picks up jaw, dusts it off, and hands it back*
I hope he was serious about never coming back.