Hey,
Don't make fun of those deaf people. They are just like us but they can't hear.
They are just like us. Their ears may not work but it does not stop them from living. They work harder to live their life with equal rights. It is a long battle they fought. Please pay some respect and treat them equally just like you would treat your friends and families.
What you could have done is buy the gumball machine and didn't realized and found the 'lost money' and return them the money and keep the gumball machine.
Please respect the human being regardless of their races, religions, ages, orientrations, and capabilities.