how do I delete my account

The option available is to deactivate.

Copied from FAQ

How do I deactivate my account?
You can deactivate your account on the page shown below. First, click the Deactivate Profile link (if you are a MinglePlus user, you will be prompted to cancel the premium package before deactivating). After doing this, you may be prompted to confirm the deactivation and to fill out an optional survey. At the bottom of the survey page, click the Continue button. Finally, you will see an "Account Deactivated" message. Click the Logout button at the bottom of the page.
Deactivate
*notes: In order not to get anymore emails from us, you will need to unsubscribe before deactivating the account.

How do I delete my account/profile?
It is not possible to delete Mingle2 accounts/profiles on demand. If your account stays deactivated for some time, though, it will be completely purged in a future site cleanup.