We are profoundly sorry to have been so much trouble to you.
Advanced English Dictionary
+adverb 1 in a way that has a very great effect on sb/sth: a profoundly disturbing programme + We are profoundly affected by what happens to us in childhood. + She was profoundly shaken by the news. 2 (medical) very seriously; completely: profoundly deaf
Random quote: We shall never know all the good that a simple smile can do.: Mother Teresa