Nedbank: Placed me under bad debts with no signed contract

I would like to know how can you place me under bad debts on my credit reports if I there is no contract that I had a credit card with Nedbank. No one can assist me with a signed contract. Cause I never had a credit card with them.

I am in a transport dilemma and I cannot buy a car due to Nedbank that listed me under bad debt.