You might be used to hearing the same complaints all the time. The type you can fix with your eyes closed. But your customer doesn’t know that, and it feels pretty unique and personal to them.
Empathize with them before jumping right into your blindfolded performance. Repeat the problem to show your customer you’re listening and care about their concern.
Ex: “You never received your package? I apologize for the inconvenience. I’m sending you a replacement that will be shipped overnight.”
Try placing a sticky note on your desk to remind yourself to start anew with every customer.