Nope - that would precisely NOT be grounds to increase rates. The current rates submitted to (and approved by) ICASA allow for sufficient profit without the interconnect charge. The interconnect charge is simply meant to cover the cost of the carrier who terminates the call. ICASA, as parliament and the protfolio commitee recently pointed out, should not be there to guarantee profits for the the networks, they should ensure "fair" competition and justifiable fees charged to consumers.
Have you a link to how and when mobile rates are approved by ICASA (not talking about interconnect fees but retail rates)?