Simply replace the unfilled areas such as "" and "[date]" with your information.
As was stated in our letter dated [date], we should be receiving our financing by [date].
In view of the above, we would appreciate your extending the date for our payment of our account until [date] This will enable us to make sure that all of the appropriate documents have been prepared.
We appreciate your courtesies, past and present. It has been a pleasure doing business with your company and we look forward to years of productive association.