hi its been a while but your free download thing will refresh after a few hours and complete
Mega used to give you a gig or so of download every few days, now I think it's down to 1 gig a month for the free portion. It sucks, but if you have android you can use the .apk file and then list chrome as a trusted downloader in your settings. If you're using PC or Apple I'm sorry, but I don't have any recommendations to help.