I received calls from this number three times in two days.  After three rings they hung up.  I called the number back and spoke with a representative.  I am listed as a contact for someone who has their system and my number was called mistakenly.  If they are checking their system maybe they just call and hang up when the person answers as sometimes it is a daily call to check on their welfare and not to have a conversation. If you don't know why they are calling you, call them and ask as it may be legitimate.  If you have no business with them ask for your number to be removed from their list.