Infinite loop trying to extract .gz or .zip

On my Mac OSX computer when I try to extract .tar.gz file turns into a .zip file. I try to extract the .zip file and then it turns back into the .tar.gz. I’ve tried extracting these files in the command line without any luck. I’ve tried downloading other file formats from my server but I’m still having difficulties. I can’t extract the file.

https://wordpress.org/plugins/backwpup/