In Florida if you request a Cease & Desist letter to a creditor to stop harring telephone communication,?

aren't they legally suppose to continue with mailings? My mortgage was bought by Saxon & they call every month to see IF we've paid (which we always pay on time & pay additional towards principle) but they continue to call so I sent the letter but now they are saying that will stop ALL communications including mailings of billing statements! That can't be right!? HELP please