Telkom Credit Vetting Declined

I recently app**** for a new contract (R259). On the call with the agent everything went through smooth and she told me i do qualify for the contract after accessing my Income and expenses. I also know for sure that i should qualify as my credit score is goo and i have less expenses, so in terms of affordability I can guarantee that. Minutes later I receive a SMS saying that it has been declined due to credit vetting. ***! Yoh I wasn't expect that and i am in urgent need of the device.

Please explain to what is this credit vetting and how did i fail it.