Free Me ... What!

<p>I recently ported to Telkom for the Free Packages and activated the FreeMe 20Gb. On the website this is the product features: </p> <p> </p> <p>20GB data<br />Free texts<br />Free IM (includes WhatsApp, Viber & BBM)<br />Free calls to Telkom mobile <br />Free calls to Telkom landlines<br />Free calls to all other SA networks<br />Free itemised billing<br />SIM-only options available in store<br /><br />MY QUESTION: Why must I have airtime credit for 087, 010, 020, 030 (VoIP Numbers), are what NOT OTHER SA NETWORKS? (Free calls to all other SA networks)</p> <p> </p>