Approved, congratulated then suddenly declined!!

Hi, I app**** for a Nedbank credit card on the 23rd, no one called to update me. I called in 3 times, i was told it's being validated each time. I then called on Friday the 30th and was told it was approved, congratulations and that they will call me today to confirm which bank I need to fetch my card at. Again today no calls so I decided to call AGAIN. Now I am told they cannot pick any application up on their system so we did a whole new one only to be declined!! I turned down two other credit providers because Nedbank said they approved me now this...I would like to know how I was congratulated on Friday but today I'm declined and has messed all my plans up with others ..please let me know!!