Start out by thanking the customer for their comments, then go forward to an apology and Whatever you will do to produce the knowledge better for future time.  ・He reviewed all his notes the evening before the big test. : 大事な試験の前夜、彼は全てのノートを復習した。 For at the time we can say we like https://www.youtube.com/watch?v=WD90friLfsQ