When you leave a voicemail do not use your full name because that immediately raises a red flat that you are a salesperson making a cold call. Instead, say your first name only followed by your company name. This will make your customer feel that you are much more familiar with each other than you really are. Saying your last name would defeat the whole purpose of demonstrating familiarity.
That’s not to say strip all emotion and personality out of your voicemail, but be yourself! Presumably, you are leaving a voicemail with someone because you want to continue a conversation with them either by phone or in person. What will they think if the “personality” of the voicemail doesn’t match the one in more fluid forms of correspondence? Knowing how to leave a voicemail that is equal parts succinct, professional and courteous can be hard for those not accustomed to doing so.

Friends and colleagues speak to each using first names only. So do people of authority. They do not call each other and leave voicemail messages asking for Mister, Miss, or Mrs. Therefore, when you call a person you want to do business with and you leave a voicemail message, refer to them by their first name only. Don't say mister, miss, or misses. Don't say their last name. Begin your voicemail message by saying only "hi/hello" followed by the person's first name. Or, you can even forget the "hi/hello" and just say the person's first name. That is how you show confidence and authority and separate yourself from weak salespeople.
To force close Phone, on iPhone X and later swipe up until you see the apps in task view, then swipe up again on Phone. On iPhone 8 and earlier double press the home button, then swipe up on Phone. You will see all the open app cards.