HDFC Bank — credit card

I am ahdfc credit card holder few time back through hdfc phone banking service they offer me a credit card and one assist insurance policy. Due to non requirement of this insurance policy i cancel they policy but they take rs399 on 6/07/2017 cancellation charges of this policy they never inform me or intimate me for their cancellation charges. After that they deduct rs 564 by the name of auto pay. I just want to know if i cancel the policy so why they take cancellation charges without informing me after that they deduct rs 564 without any of my purchasing, it's such a bad experience of my
Kindly refund my money back as soon as possible. Or arrange a call asap