Take a piece of parchment or fine quality writing paper and inscribe the name of the target. Write it in a circle twice, so the ends meet. As you do this, concentrate on the person's face and your desire that they call you. Then, while still concentrating, put a needle through the center of the circle created by the name.
Place the charm by the phone. The call will come within 5 minutes, 5 hours, or 5 days, depending on how well the spell was cast and how much will power was used. Concentrate on the person and meditate after.