No, you just need to get used to it and decide on a professional response. Remember - you are catering to the absolute lowest common denominator of human beings when you sell online. Some of these people are so clueless, they cannot drive a car, let alone post something! They probably know much more about the inside of a Centrelink office than a Post Office. :^O So, maybe just reply with Hi, thanks for your message. I understand that you might be concerned about the inconveniently long delay. I am sure yo remember that you only paid me on Saturday night, and whilst I camped outside the whole day on Sunday so I was first in line, they still wouldn't let me inside the Post Office until 9:00am Monday morning (today). This was only necessary because my normal delivery pigeon was molested by a rabid kookaburra, otherwise you would have heard his pecking on your window sometime on Sunday morning. Always remember that we aim to please. Don't forget to mark down my postage DSR stars, and spend a few moments to think up a decently obtuse reason to give me Negative Feedback. Kind regards, your dutiful seller.

:^O  :^O :^O