Excuse me. I'd like to make a complaint.
Oh, I'm sorry to hear that. What seems be the problem?
Your bank service is just a full. I was here last week to take care of some banking transactions. The line was very long since there was only one teller. I asked a bank employee to bring in another teller, but he said they were too busy with more work. I'm going to change to City Bank.
Let me apologize for the poor service and unhelpful member of staff. It seems that you went through a terrible time getting your business done. Why don't you come into my office where we can talk without any interruptions?