True, in the world of the internet we cannot easily trust all those who are not real in front of us. They are all our virtual friends, just like me and you, we don't know each other and I could get more incentives to commit fraud for that reason.I search online and I'd never see another way of buying Bitcoin other than that have mentioned above. But I was not convinced if it runs smoothly, in fact, this way of buying bitcoin isn't popular unlike in using exchangers. And even me, I have no trust this thing and the risk of being scammed.
But if I were you, I supposed not to use phone credits. There is no hard of having an account in any reputable exchanges where you can think about the safety assurance. I don't think if this will matter you much but I was not pushing you as well to change your mind if you already have decided. But just to remind you about the risk and you should have to put it in your mind otherwise, you'll be in regrets after.
But with phone we can access internet also penetrate in those platform, what are the reason you portray that know one sell bitcoin with phone credit?I see that currently no one sells Bitcoin using phone credit, and even if it does, I don't guarantee it will be very good to do so at this point, I think if you really want to buy Bitcoin, it's better to use an exchange like Binance, KuCoin , Bittrex, and other exchanges because existing exchanges like the ones I mentioned are real, if you buy on an exchange that actually has nothing to lose, but if you buy them on a site that doesn't seem real, you are at great risk of losing money.