Bitcoin stolen from my Blockchain account. How is that possible?

[ydix]

I had 2 step verification in my Blockchain account even thought without any kind of notification or email to me my bitcoin was stolen from my Blockchain account!! We sent many emails to Block chain about this but every time they replied irrelevant answers which we can not accept something like it happened because of virus and malware. Blockchain account from where Bitcoin was stolen Blockchain removed all transaction history and they also did some changes in transaction which really cause doubt about Blockchain activity, so anyone who experience the same situation or anyone who can explain me how is that possible?

[BurtW]

I may be able to help you.  Questions:

Do you mean you had a wallet at blockchain.info?

I assume that is what you are trying to say.

If so then did you have an older wallet or a newer HD wallet?

If it was an HD wallet then you would have written down a set of random words.

 Did you do that?