Did you pay via PayPal? It's very annoying when you get a "payment confirmed" message for any service, but there is a particular problem with PayPal of which most people are not aware. I have integrated PayPal into a number of online stores and have found that PayPal payments are a little like attaching cash to a brick and throwing it into your neighbour's yard and then texting him to let him know you paid the bill. You really don't know if your neighbour has received the payment, its still hanging about in the garden somewhere, or you didn't bother attaching the cash to the brick. The recipient will get a "paid" message, but the reality is PayPal can rip away that status at any time. As a result, some companies have taken the view that a "paid" state from PayPal is about as trustworthy as a fox left alone in a chicken coup; especially when expensive items are involved. When it comes to PayPal, they almost always side with the buyer. If the buyer complains that they did not receive the item, even if it was signed for in blood, PayPal will usually perform a refund.
I'm not trying to defend DJI's practices, which can be very annoying, just to raise the issue that PayPal is very annoying for sellers. The only reason most sellers use PayPal is because customers demand it.
If you paid with a CC, expect a two or three day delay.
If you paid with a debit card, it should be instant but usually still takes two or three days.