How to remove your Wuala account
From their FAQ (https://www.wuala.com/en/support/faq/c/5):
How do I delete my account?
Please write us an email [delete-account@wuala.com]. It is important to state your username and send the email from the email address you specified in Wuala.
Helpful Trick: Removing online data
Publicly visible text/images often aren’t properly removed even when you succeed in removing an account. Try editing or removing them manually before removing the account itself. If you’re unsure what happens to your tracks: this can be found mostly in the Terms of Service/Privacy Policy; otherwise you can always contact Wuala and ask personally. By the way, removal requests don’t necessarily mean your data will actually be removed (e.g. due to legal obligations).
Helpful Trick: Remove third-party logins
If you signed up for Wuala using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Wuala. Click here to find out how.