Fraud transactions OXIGEN

Hi ,
This is regarding the transactions done in my accounts with the transaction remarks ,”BIL/****/OXIGENPMR/*****”. I am a customer of ICICI Bank India , Bangalore.
These transactions have been occurring since 22nd July 2014 , and its almost everyday, money is being deducted from my account .The summary is :
Total money debited in jul 2014 is Rs.860
Total money debited in aug 2014 is Rs.2536
Total money debited in sep 2014 is Rs.2325
Total money debited in oct 2014 is Rs.730
The above trasactions are illegal and fraud and have not been done by me.
The reason given by the bank is that after my prepaid number got deactivated, the subscriber gave this number “9986234065” to some other person. And that person somehow got hold of my account number and made these transactions.

Following are my concerns :

Even after lodging a complaint with the ICICI bank and my debit card blocked, still another transaction happened on 6th Oct 2014. The bank had no clue as to how the transaction happened.

I tried to update my number while in India and even in USA.I was not able to do so , even after I cleared the security questions because the bank said its not possible to update phone number by talking over phone and even not through online.
But the bank authorises a person who is using my number(not the same sim which I had been using , just the number) to do transactions even though I have not given him my debit card, userid/password or account details. The bank is just assuming that the person who is using my phone number is aware of my account number. The person currently using my number has denied it and even I also never disclosed my account number to anyone.
This is a big fraud and the bank still fails to take any action.

I have done business with this bank so long but this episode has completely terrified me. I no longer feel safe. How can the bank let go of a transaction with only a registerd phone number ?

I want a refund for the fraud transactions that happened because I don’t see its the customers fault. How can the customer know that an unknown person who does not has my debit card/account details/ internet banking userid /password will be able to pull out all his banking details if he gets to use the registered number.

Another point is though the bank refused to update my number previously on phone or online, but after this fraud, since they were not able to stop this fraud transaction, they asked me to drop a mail for deleting my number from my account. So does it take a fraud , to let ICICI make easy for the customer to update his number?

Please do the needful.