Vodacom
2 sim swaps later and my phone still can't connect

I have a Galaxy S3, which I had repaired by an approved Samsung service centre. I have subsequently done two SIM swaps to get the phone back on the network, but these SIM cards won't connect. However, I have used per-paid SIM cards and the phone works fine, I have also placed my iPads SIM in the phone and it connects perfectly. Nobody can give me an answer as to the cause of the problem. I logged a service request to the technical division who were supposed to get back to me within 48 hours, I have now been waiting for close to 140 hours, without any feedback being given. I find this couldn't care attitude unacceptable and am fed up with being shunted from pillar to post by incompetent staff.