According to an Association of Psychological Science article, there are three critical elements in an apology when customers are wronged. The second element is an explanation why the problem occurred.
Kathy and I went to a new restaurant. The tables were covered in dishes and no one seated us. We considered leaving when the owner came over and apologized.
He said, “One of our employees asked if he could go to church. I underestimated how much help we would need and said, “Yes.”
Due to his candor, instead of leaving, Kathy and I pitched in and helped.
Psalm 32:5 says, “I acknowledged my sin to You, and my iniquity I did not hide…”
Unless your customer understands why your mistake happened, they may fear a reoccurrence. Acknowledge your mistakes.