Okay so this is ridiculous.
I recently uploaded a remix of How Low by Ludacris & Head Splitter by Getter.
I obtained rights to upload this remix via Getter's Management, and the subsequent song "How Low" has been up for more than 7 years and is now free to remix.
However, the copyright team didn't care - when I stated that I have the rights to upload it, they reviewed it for a day, then proceeded to reject the upload (which happens to be a filthy mix that would generate many plays and followers).
Soundcloud's copyright team needs to review this again, and let me upload the file that I HAVE PERMISSION to upload, or I will pursue legal action.