Why does POS receipt list random person as customer?

Earlier today, we received a call from a customer who said their POS receipt listed some random guy as the customer. We initially thought it must be a mistake on the cashier’s part. However, neither the phone number nor the email are similar enough to make that seem logical. Moreover, this customer is alleged to have placed 25 orders in the past six months! We have some loyal customers, but that’s a lot.My hunch is some sort of bug is adding this same customer to the order over and over again. Anyone experience this??