That was astonishingly good customer support. I sent a support-request email to comiXology (maker of various comic-reading apps for iOS) at 8:29 pm Pacific time last night, expecting that I might get some kind of autoresponse answer sometime in the next few days, maybe. Eight minutes later, I got a thorough, friendly, knowledgeable, personalized response from someone named Pat, a response that completely answered my question and gave me additional info and another approach to try in case the first suggested course of action didn't work. I tried the suggested approach, and it worked.
This is some of the best customer support I've ever received. I'm amazed and delighted. Thank you, comiXology!