Received ₹11500 from unknown source

Today i received 11500 in my bank acc which i didn’t check but i got a call around 6pm this guy introduced himself as the cashier of bank (he named my bank and branch correct) and told me , aapke acc me 11500 aagye hai glti se aap monday bank aa jana ek bar , to which i said why i will come and i will not come as i am not free so he said aapko aana hoga sir nhi to payment reverse kara lenge , i said i’ll not come and i disconnected the call after that he called me twice but I didn’t pick up . I checked my bank balance and i have received the amount . Is it a scam or what i dont understand what should i do , banks can easily reverse false transactions then why he is asking me these sort of things . Wil i face any legal action if i spend or transfer that amount somewhere