unauthorized debit order for credit card I never accepted!

I have been in the financial services for over 10yrs and never have I ever felt so confused. I app**** for a credit card almost 3 weeks ago and 2 weeks later someone called me to get authorization to pull my bank statement from my bank and that was the last time I heard from Nedbank. This morning I wake up to an bank sms notification that NEDBANK has debited my account, mind you no one called me to discuss my approval; T&C's and interest rate given because that was the main reason I app**** since the bank I'm currently with gave me 15% interest rate. after being transferred from one person to the next only now I find out that my card was approved with 17.5% interest rate on the 27th Nov 2020 and they tried calling me on my old number which I last used four years ago. I need to know who gave you authorization to debit my account for a credit card I don't even have or have used in anyway!!!!