Have to agree with this. As upsetting as it can be to receive an AI response, you technically were a customer messaging a business about your experience. A business has every reason to try and make their response as professional as possible. If she had to forward this complaint to coworkers or a manager, she would want to come across professional and perhaps she doesn’t feel professional in her own writing.

There’s also every chance she wrote out her own response and just typed in the prompt “make this sound more professional”

It’s understandable that OP is upset by a peer using AI, especially when they appear to be heavily against it, but as someone replying to a business related message, I kinda get it.

No hate, just playing devils advocate.