Hi, I hope this is the appropriate section. During the last few days I heard two different colleagues of mine undergoing the same experience: they were using Facebook's mobile app, they tapped an ad and were redirected to whatever stuff; then they found out their phone credit had been billed without their explicit consent, just one single click on a banner on Facebook! Both my colleagues called in order to get refunds but they didn't manage in doing so, and it wasn't worth it anyway considering the small paid amounts. Can anyone explain me how is that even possible? I'm aware of direct carrier payment providers such as Fortumo, but as far as I can understand at least a phone number is required in order to bill anything, and Fortumo prompts the user with some GUI before billing. Thank you.