They were right -- it can take the modem a couple of days to update itself when it's newly installed.
Before they can address your speed concerns, the Hughesnet staff on this site will need you to follow a specific protocol, which is outlined here: https://community.hughesnet.com/t5/Tech-Support/Think-you-have-slow-speeds/m-p/110034#M74607
Plus, 0.7~1Mbps is plenty sufficient for YouTube videos*. Speed isn't the issue, latency is. It's buffering because it takes a around a half second to handshake with the server, because... satellite.
*Edit: in 320p.
We're closing this thread since we never got a reply from you. If you still have concerns, please start a new thread and include the results for speed tests (using the instructions posted here by @maratsade) so we can more effectively help you.