Canara Bank — Unacknowledged transaction without OTP

Sir, last night I got a message saying that 999/- has been deducted from my account. But I didn't get any OTP or any acknowledgement regarding the transaction. I have talked to customer care and got to know that its a fraud. If an anonymous can have an access to my account without my acknowledgement how can I feel secured putting money in your bank? I never shared any kind of personal information to anyone. So kindly resolve the issue and make me feel that my money in your is safe and secured.