Koi smart koi dumb

In our regular coffee place,“ no change for 1000 rupees, can you pay by card please?” The card never came back and the fool I am, I never noticed until the e-statement reached me this morning. Someone has been on a shopping spree. Seems to be a first timer as thankfully it all adds up to within 5 thousand rupees in two weeks. Could have been so much worse. Blocked the card but wondering should I go and give an earful to the coffee shop staff or just forget it as a stupid, expensive mistake.