I will sincerely apologize to let him know that although I worked hard to fulfill her request, I still could not satisfy her and asked her what I could help. It is possible to ask my other work partners for help, to provide useful advice, to meet her requirements without affecting the next customer appointment. If there is not enough time, I will ask the manager for help to see if I can send her some free items or coupons, or re-schedule. If the client does not believe that my ability can be what she imagined, then it may be necessary to replace other colleagues to help him solve the problem and serve her.