As the merchant, you are responsible for handling customer complaints and providing support when issues come up with an order — whether it's a missing item, incorrect product, or a delivery that didn't arrive. Since your customers interact directly with your store, they’ll look to you for answers and resolution.
That said, if the issue is clearly related to the delivery (e.g. a driver no-show, late arrival, or damaged package), your account manager can help investigate with the delivery partner and escalate as needed. But from the customer's perspective, you're their main point of contact — so it’s important to respond quickly, take ownership, and let us know if you need support behind the scenes.