I'm not sure how to do another function to delete the name and phone.
Here is the code I did:
(defun incluir (Agenda NomeTelefone)
(cond ((atom A) (cons NT 'nil))
((equal (car NT) (caar A))
(cond ((existeFone (cadr NT) (cdar A))A)
('t (cons(cons(car NT)(cons (cadr NT)(cdar A))) (cdr A)))))
('t (cons(car A)(incluir (cdr A) NT)))))
//função existeFone
(defun existeFone (NT A)
(cond ((equal NT A) A)
('t (cons (cons(car NT)(cons (cadr NT)(cdar A))) (cdr A))))