Explain your process to the customer
Sometimes customers who are confused or unhappy start to freak out a little in their emails, so I want to give you some ways to respond to let the customer know exactly what you're doing to solve their problems. The key is to be transparent. When you use words that make your actions clear, customers calm down and accept your help, and even better, they write fewer followup emails. So let's say a customer emails about a refund for a defective watch, and asks, "When will I get my refund?" A standard form letter response would say, "Our records show that we received "your wristwatch on October 16th." Our records show? This is a tired old phrase that makes no sense.
The fact is that you took action. You reviewed the record, or you looked at the customer's account, and that means that you can give him accurate information about what will happen next. A simple rewrite is all you need. I checked our records and I see that we received your wristwatch on October 16th. Next, give an explicit timeframe in which they can expect a solution.
Source: https://www.linkedin.com/learning/writing-customer-service-emails/explain-your-process-to-the-customer