Do you need to retain the data from the calls that are not latest?
If not, what you could do is make a new column in query editor that is a combination of CallDateAndTime & Call From & Call To. Then sort decending by CallDateAndTime and remove duplicates in the combination column.
This should give you the latest call from a specific number to a specific number on a specific date.
Please post some sample data so I can better understand what you are looking for if this does not solve it.
Thanks Nick, I did think of that but Power BI doesn't support the remove duplicates functionality with DirectQuery & it would change to Import which wouldn't work for us as it's a dashboard/report fed by a SQL table and is updated automatically throughout the day.