I don't understand how you think you were scammed. NOWHERE in any bill, or online description, did it ever, in any way, shape, or form, provide pricing for email. In fact nowhere does it even provide an option for getting internet without E-mail for a lower cost.
In fact years ago, Cox STOPPED providing email addresses to new customers, and they paid the same for their internet service as you did, WITH E-mail. Does that mean Cox should have charged you more for your internet service WITH E-mail, than they charged their new customers for internet service WITHOUT E-Mail? If so, should they bill you retroactively from the date they stopped providing E-Mail addresses to new customers?