Quality of the voice

Last night an unpleasant telephone conversation broke out between a bank customer service representative (Bank) and me (RY).
This is an extract of the conversation.
RY: “Please don’t raise your voice at me. After all, I am a customer!”
Bank: “That is my normal voice. I am not raising my voice at you.”
RY: “Well, at the receiving end of your voice, I feel that you are raising your voice at me.”
Bank: “That is my normal voice.”
RY: “Perhaps you should have some feedback on what you sound like.”

Well – to be fair, there are lessons for both ends of the conversation.
For “Bank”, she should collect feedback on how she sounds on the phone in particular when explaining a complicated case of inquiry.
For “RY”, he should learn other ways to deal with people that come across as rude or arrogant besides telling them off.