How can I stop Twitterfeed?

A while ago I set up Twitterfeed to repost updates from my blog. I don't want to do that anymore but when I log into Twitterfeed it doesn't show my feed so I can stop it. Is there a way of stopping it within Twitter by blocking it from using the API or similar? Also I get a 404 when I click on the API link at the bottom of the page.