During the first twenty days your service is in a "relaxed bandwidth" state, meaning your data allowance is constantly reset during this time. HughesNet does this as a courtesy to allow customers to update or upgrade their devices to current without it affecting what would be their normal monthly data allotment. After these twenty days your data will start being counted normally.
The twenty days of data resets are mentioned in the Welcome email from HughesNet.
AMD FX-6100 | Samsung 250GB 840 EVO SSD | Western Digital Blue 500GB HDD | 16GB DDR3-1866 | EVGA Geforce GTX 550ti | Windows 10 Pro 64-bit