Hi, I have a Telkom flla contract phone with sim with anytime call free telkom-telkom landline package, a mobile cell c contract package with 100 minutes free, and a prepaid 40c / min voip line. The idea was to call using the telkom line for all telkom landline calls, use the mobile cell c for mobile numbers and the voip as a secondary line. Since many telephones have numbers ported and not knowing whether the number is Telkom landline or mobile number, I end up with my Telkom bill with additional costs for "other networks".. I am presently using a dual sim phone with Cell C sim on sim 1 and the Telkom sim on sim 2, as well VOIP line using a voip app. Thus I have 3 lines on my mobile phone. The question is how to use my lines cost efficiently by routing my outgoing calls through the correct network.