https://help.daybreakgames.com/hc/en-us/articles/217509478-Launchpad-is-stuck-or-won-t-download If these steps don't work, put a ticket in with support and they can help you troubleshoot the issue.
https://help.daybreakgames.com/hc/en-us/requests/new No response from filing your ticket? That would be very strange.
If you need more hard drive space, um, maybe you should buy a cheap drive? Prices are extremely cheap these days for terabytes of storage. And if you think it's a matter of your drive not having space, what do you expect support to do about that other than tell you to get a larger drive? I'm confused.
I personally have not experienced the issue, but a quick google search suggests Deleteing The Folder: C:\Users\ <USER> \AppData\LocalLow\Daybreak Game Company\Digests\DC Universe Online Live where <USER> is the windows user you have the game installed on. and then relaunching the game. *solution was for H1Z1 and Planetside 2, however Daybreak uses the same launcher for all their games.