We don’t know why you’re delayed, only Apple does.
The best experience has been pickup or purchase directly at and thru an Apple Store.
Using a carrier, dealer, third party retail store or delivery by a UPS / FedEx adds the potential for delay and frustration.
I have been your position. I would Check your options to purchase Directly from an Apple Store and cancel your original order. If that option is not available you will continue to be at the mercy of your tech stores and local carriers who will always blame Apple when a new product is in limited supply.