Somehow it got turned on. There is no charge to have TravelPass on your account. You're charged only when you use it on travel. You should be able to turn it off yourself if you don't want it on.
Depending on your plan, TravelPass may be an included feature. For your peace of mind, TravelPass will only activate when using your service in a foreign country. To learn more, please click here: https://www.verizon.com/support/travelpass-faqs/#travelpass
~Izzy
