They cancel the charges to get Verizon to call them. Worst case here is the credit card company works with Verizon and the customer to get the second wrong charge removed. I believe this is what the op mentioned.

You also have fraud here in that selling a phone only with accessory purchase, is sale by deception. And even if a reseller they are under Verizon Wireless as their agent. No skirting the responsibility they sell the service for Verizon.