ICICI Bank Limited - ICICI Bank fraud, No proper enquiry, unsecured account

On 4th OCT 2010, I received message that at a debit card purchase from Yatra.online was made amounting to Rs 4177/-. I lodged complaint to the Santosh Nagar, Hyderabad branch where my account is existing. I further enquired from Yatra.online and came to know that some airlines ticket was purchased. The matter was informed to the ICICI authority.
After 35 days of enquiry I was intimated on mobile that my debit card was used which is totally false and vindictive as the debit card was with me only and neither I have made any purchase nor anyone know my debit card detail except ICICI server administrator.
In view of this the account at ICICI bank is very unsafe, unsecured. The bank authority has made a mockery in the name of enquiry. They even not informed me where the debit card purchase was made or any detail further.
The bank should take the responsibility and refund the amount to my account.
A Basu
ICICI SB A/C no: ********4239