Nedbank Personal Loan DECLINED

Good day, on the 17th April 2019 I called Nedbank Personal Loans to see if I can qualify for a loan as I am desperately needing to purchase a car. I was told on the phone that I have been pre-approved and all I needed to do was send a copy of my payslip and ID. I was told I had five working days to do so, so I sent it on Tuesday the 23rd April 2019. (Still within the five days) I have now been contacted to say that my loan has now Been DECLINED after I was told that it was pre-approved??? I have found a car, after being told I am pre-approved for my loan and someone from Nedbank was just going to contact me to go through the contact and sign. Now I don't know what to do as I dont understand how I can be Pre-Approved on a RECORDED CALL and now all of a sudden I am declined. I spent about 10 mins on the phone doing my application and was Pre-Approved as well as sending my documents, so all of that time is now wasted as now I'm being told my loan is apparently DECLINED. I have been banking with Nedbank since I worked with them and I have had a personal loan before. PLEASE can someone contact me to resolve this as I find it very UNFAIR and UNPROFESSIONAL to be told I'm approved and NOW ALL OF A SUDDEN I AM DECLINED WHEN I HAVE ALREADY FOUND A CAR TO PURCHASE.