That's a cute response, but that's not how applications are written and presumably you know that.

I'm not excusing this. If they did it the right way they'd have 1. Set a date to cancel the existing program 2. Sent a targeted email to everyone enrolled in it which said, "We have major changes to the unlimited delivery plan effective xx/yy, if you would like to continue please follow this link and accept the changes or you will be opted out" 3. Cancel the old plans across the board on date xx/yy

But hindsight's 20/20, their explanation is more that plausible, and their response is more than adequate. Do they need to put on hairshirts and scourge themselves?