Old Man Wants to Slap Me Over Pizza

I'm a pizza delivery driver and last night an old man said he should "Bitch Slap" me for not bringing any Parmesan Cheese and Red Crushed Pepper packets.
Things to learn:
1. Defuse situations by walking away or laughing it off.
2. Don't let insults get to you.
3. Fast Food Industry will make you a stronger person.