Customer can't contact discovery bank

All my details with discovery are correct. My ID, my telephone number and my email. I know it is correct as I receive sms' and emails from them. However, discovery has not linked my details together. I tried calling them, but I need an Otp. I give them my ID, but the number to which they send the otp isn't my correct number on the system. I can't change my number as I need an otp. To get to speak with a service operator, I need an otp. How can I get my details right when I can't even speak with someone.