Have you used the email that you used to register on a different account? If so, that it is the reason why, and you will never be able to delete the account (I think, don't quote me on that). Otherwise I am not sure. If the first option isn't correct then PM a mod. Umm, I think the only way for you to fix this is to change the email linked to the other account (In case 1) to a different email, then try to delete the account and then relink the other account to the email which you want. Otherwise I don't know what to do.