Contacting Apple Store for order pickup extension

I ordered some items for store delivery. Apple brought forward the original delivery date. I will not be in the area to pick up my purchase on time (7 days for pickup policy) and would rather avoid the whole sending-back-refunding procedure. I need to let the shop know to keep my order (which is paid, obviously) and stick to the original date (they brought back the 4th of December to the 27th of November).

What are my options for contacting the shop (I'd prefer to email or chat rather than call)?

Also, suppose you order a laptop and Thunderbolt cable for it. How come the cable is delivered in a day or two and then kept for only 7 days before the main part of the order is expected in two weeks, making you make multiple trips (should it not be kept altogether at least until the last item arrives?)?

[Re-Titled by Moderator]