Calling a Dead Client again!!!

Today at 14:17 I once again receive a call from Vitalaire wanting to speak to my deceased dad. On asking why I get told they want to check how their customer service is and if he is happy with them and his machine. Really this has happend before and reported before and I was promised that his account was closed and even sent a copy of proof that the account was closed and told they would never call again. Now seven days before his first Angelversary I get the dreaded call again. What else must be done to stop this ? This is emotional torture.