State Bank Of India [SBI] — cc debt collectors

I just received a call from[protected] and the person on the other end identified himself as the manager in SBI and asked to talk to a family member who had defaulted on their cc. I said u have called a wrong number he identified my name and said you know that person let me talk to him. When I refused he threatened me saying a warrant has been issued and the police will come to my home and arrest us. Which is alarming. This has really rattled. They keep calling from different numbers and cause mental torture to me and my family members. Please help. My mom is already a mental patient going through treatment in Noida. This is effecting her progress and she is relapsing from her mental well being. I need this to stop.