If you search for "recargas Telcel gratis best," you will find websites claiming to "inject" credit into your number if you provide your phone number and complete a "human verification" (which usually involves signing up for a paid SMS service).
If you have a Postpaid plan (Renta) or a high-use Amigo plan, you are likely accumulating . Many users forget these exist! You can redeem these points for airtime (reloads). recargas telcel gratis best