Source for account deletion: https://support.netflix.com/en/node/407
Further, the ToS and PP provide some info.
However, as you can read on that support page, only deactivation is a possibility for Netflix. That’s a black list anyway.
Furthermore, the support page and the ToS name two differing ways how to cancel your account, each didn’t work for our test account. Netflix, is it really that hard to be consistent and clear? Compare the above-mentioned to this if you like: https://www.netflix.com/TermsOfUse#ongoing
So, what’s left to be done? If you no longer wish to have your reviews publicly posted, you may delete them by going into the “Your Account” link on the website and selecting “Reviews”. That’s one thing, if you would find it important to delete those. For the rest, and that’s always the last thing you could do: simply contact them and request deletion.
This is also one of the sites for which it seems nearly impossible to find a proper email or webform for contact. You could try this: firstname.lastname@example.org
Obviously Netflix may not be allowed to delete all your data because of legal reasons, which is mostly the case with commercial sites. You oughta know that by now.