Failure to provide reasons for contract decline.

Hi, on the 1st oct 2019 i went online and chose to buy a data contract, i received ref number and a consultant called me to confirm details and all info was given and a credit check was done and was approved on the phone. I was told to submit documents to complete application. I got all docs ready by 2nd oct 2019 and called to confirm my application and documents for emailing. I was told that i have been declined without reason. I made numerous calls to mtn to clarify what the issue was as i am not in debt with mtn and failed to get a reason for decline. In fairness i should be told why i have been declined. I demand an answer to ressolve the issue.

What i dont understand is i get approved on the phone and by close of business declined.