Hi. I don't really use steam much and never played any heavy games from it until recently.

The game am playing needed a huge update of 50Gb and i was downloading it then paused it at about 30% then when i un-paused it reset everything? Where i live wifi is not unlimited and i actually pay extra money to get these huge updates done and also the disk space that the downloaded part took did not reset.
What i want to know is if its going to redownload everything really or what and what happens to my disk space as well will it just be an extra 20Gb of duplicate resources ?