By you not knowing where to get your ID, do you mean to say that you can't or dont even remember your login ID?, that is; ID you used to login?
If this be the case, have you tried using the "forget password" feature? If you have an email address linked to your account, you should simply enter the email address in the next screen after clicking the "forget password" button, then solve the captcha and click the "reset password" button, you should recieve a new email address with either a new password, which you can change later, or a link to set a new password, and afterwards, you can login with your email and your new password.

I hope this helps though, since there are possibly no customer care to help.