smart device was approved now declined

I app**** for a smart device from fnb i received a call from a person named Charmaine Ndimande advising me the application was approved i would expect delivery within 10 to 15 working days i later received an email advising me it was declined i called fnb on the 14th april and advised them what has happened i was told that they are investigating and They would get back to me i then Received an email again telling me it was declined with no reason what so ever to say why was it approved then declined.