Telephone conversation

Hi everybody!!!
I couldn't join to this lesson.But I asked my friends about the lesson.They said that the lesson was about telephone conversation.I am writing below my telephone conversation example.
Gokhan: Hello, this is Gokhan Guripek calling. Could I speak to David Jackson?
His asistant:Just one moment. David Jackson?I am afraid he is tied up at the moment. Shall I ask him to ring you back?
Gokhan:Could you put me through to his secretary?
His asistant:I am afraid she is tied up too.
Gokhan:Oh ok. May I make an appointment for tomorrow?
His asistant:I am afraid he will not be here tomorrow. How about on wednesday evening at 16.00 p.m?
Gokhan:That would be fine.
His asistant:Good. So that is Gokhan Guripek on Thursday the 9th at 17:00 p.m., then.
Gokhan:Thank you very much.
His asistant:Goodbye.