Unfortunately, VZW does not offer an option to block unavailable or restricted numbers from contacting your phone. As previously mentioned, some phones have the option of restricting calls to your phone to those only in your contact list, that way only the numbers in your contact list can reach you.
Also, VZW has the ability to change your phone number. There is a $15 fee associated with it, and it will prorate your usage for the month, but if you call Customer Service, any VZW representative will be more than happy to assist with providing specific details on what that means for you. If you do decide to change your number, call customer service from a separate line, with your phone available.