My game is downloaded but restarts

i downloaded fortnite from my mobile data as my wifi is slow and takes time i even played 2 games but the next day when i open the game it restarts the download from zero and downloads very slowly(on wifi) now i cant use more data to download the game pls help

Your going to want to go to the Fortnight Support page to get help. This answerhub is for the unreal engine itself for development questions. I say this only due to the fact you will more likely get help sooner on the fortnight page.