Dear Sir
I hope you can give me another project. I am fullstack experienced developer.
First of all, I would like to apologize for the delay in your project.
The delay was not on purpose or because I am lack of capability for your project, It was really an "Act of God", and I hope you understand me with an open mind.
A German proverb says "do not make friends easily, and split with friends easily".
To tell the truth, it would take more time do complete your project, if you look for another one for your project.
But I can complete your project within 20days, as I have a profound study on your project.
I know you are upset because of time, but the exchange of employees would change nothing but only causing more loss of time and money.
I am going to underbid for this project and further projects to apology myself if you accept.