@juscurrency, here's an article from two years ago. Worked for me today. https://steemit.com/steemit/@raised2b/how-to-undelegate-steem-power-in-4-easy-steps

PS: Looks like you have your SP back only aftre 5 days. Found this in the minnowbooster FAQs at https://www.minnowbooster.com/faq The command mentioned there for undelegating is even easier then the one from the article