You have not said what program you are using to download the file with. With torrents, patience is a virtue and good option.
If your program allows you to search torrents then do a re-search for that torrent, that might either refresh the seeder or tracker list the program is aware of with fresh ones. However that should not in theory be necessary. If the program requires this then it's probably not a very good torrent program.

One of the issues, not only torrents but all p2p file-sharing is the quick snatches without seeding (sharing) the file back until a good ratio for that file is achieved such as 3:1 or greater. I have torrents seeding where the ratio has reached into the hundreds to help keep that torrent alive. Even a torrent heading toward the size you are downloading is over 50:1. I have a tendency to prioritize my seeding toward the least seeded files to keep life in the torrent and prevent it dying. Some of these seedings are several years old.

It helps for both downloading and seeding if you open the program and forget about it so it runs 24/7. This might not be practical for those on bottom-end satellite, adsl/dsl, etc. connections, but some torrent programs allow you to set the seeding upload bandwidth capacity to maximum at times when you are away from the computer (such as overnight or whilst at work) and lower capacity whilst you need the bandwidth for general times at home (peak and off-peak settings.) Unfortunately some seeders only run their program for short periods certain random days of a week or month or y. quarter, etc. and these times might be different to your timezone.

Also try to ensure your torrent program is allowed through your software firewall and is not firewalled via your modem-router. Some hosts (seeders & leechers) might only be connectable via certain protocols such as DHT which is not possible if your program is firewalled.