Dear Jose,
With regard to the download of S2 products, beyond the AWS there other ways to do it.
-1) Download the full S2 products from the SciHub using a download manager (e.g. ‘DownThemAll!’ for firefox) that is able to manages interruptions during the download.
-2) Use the routine developed by Olivier Hagolle that allows to download a single S2 tile (read the discussion on STEP forum available at Download tiles)
-3) Use the USGS EarthExplorer system that distributes S2 tiles but it is not well populated
-4) Anyway, from AWS using a script to merge all the JPG2000 files in the S2 SAFE container (public available at https://github.com/kraftek/awsdownload) and open using the reader already included in the current version of SNAP.
I hope that these tips could help you, but I am sure that other users on the Forum could provide you more suggestions concerning this topic.
Regards,
Fabrizio