Mauriek, as our support have explained, your account had the email changed by using our "change email" feature that requires the user to have access to the previous email to complete the process.
We also offer 2FA but it was not enabled.
We cannot prevent an attacker if the account is not properly secured and the attacker has access to the users email, if you want extra security please enable 2FA.
What Tulkas, you still have support staff over there? Figured all your employees would have fucked off by now...aren't you finished now, close this thread and bury whats left of BTCJam in the ground you drove it into.