POOR SERVICE - DISCOVERY BANK

I keep getting sms's that I owe this Bank money. I have not had a Discovery card for over 8 -10 years. I call the call center and they cant help me because I don't know the answers to the security questions. ITS NOT SURPRISING. I have not banked with you for 10 years. ITS ********** - I do not have an account with you - can someone help me???? You get a NPS of -100% from me. NO service whatsoever.