Melanie: You don't have an ATM.
Dorothea: Them things. Russ won't get one because you lose personal contact with customers.
Melanie: Yes. That would be tragic.
I understand the sentence, but I can't find any connection between customer's and ATM. Dorothea says ATM would let Melanie to lose personal contact with customers. My doubt is Why would a ATM does such things to her?