Data contract declined for unknown reasons - failed to give explanations

I am so disappointed with the service I received. I app**** for a data contract online and asked for a call back. A consultant called me and took all the required information and said that the deal was approved but they still need to do a credit check and that they will notified me either by email or sms, if they can place an order. I did receive an sms and it stated that the order was declined due to credit vetting. I tried to call customer care for explanations, as I do not understand why they can decline my order since I only have one contract with Vodacom and am credit worthy. Getting in contact with customer care was a struggle, since they kept referring me back and forth to different numbers, until I ended up to the first number I called and insisted for answers. The lady that I spoke with failed to explain to me why my order was declined and she kept on making assumptions. I asked if I can speak to someone who can assist me with this matter but she kept on saying that all they do is to put the ID numbers on the system and it gives them the results, either declined or approved. I then asked to speak to the manager but they said that the manager was still busy. I asked them to call me back and ask for a reference number, and up to now I am still waiting for the call. It frustrates me that they can not give me answers and people from the store can't also help me.