First of all, know that these forums are for customer to help other customers. Only Verizon will be able to tell you if they will exchange your router. Contact them using the information they list on the "contact us" page.
Second, it's a router, not a modem. If you have one that doesn't have a USB port, it must be quite old.
Third, even with the latest routers the USB port isn't usable for printer sharing.The USB port isn't usable for anything.
You can buy a new router from verizon here:
If you live near a Verizon FiOS store, they might swap it if you bring in your current router.
Still, you must contact Verzion to find out what they will do for you.