Thanks to a good expert guy (possibly from the Bancor team) I have recovered my ETH to the Ethertoken and converted to BNT.
To check the balance in Ethertoken, I used this tool:
Contract Source Code Copy Find Similiar Contracts pragma solidity ^0.4.11; /* Overflow protected math functions *…etherscan.io
Then I approved and transferred the whole amount to BancorChanger. The gas for the transaction has been taken from my wallet.
Thanks again to the Bancor community