Split text into phrases of a person and an operator I have about 5,000 texts without punctuation marks.
Each text is a conversation between an operator and a person.
For example: "Hello hello how can I help you how can I find out how much money I have in my account"

How can one separate phrases between a person and an operator using machine learning methods?
I think the task you're looking for is called "Punctuation restoration" or "Punctuation prediction". An example of this is described in this paper, or this other paper.
Unfortunately I am not aware of available per-trained model that you might apply to your dataset. Honestly I think that it is unlikely that something trained specifically for costumer service calls exists, unless you want to annotate your own dataset and train a model out of it.