In order for the Reps to be able to address your speed issues, they will first need some tests to be performed. I know you've already done a few of Hughesnet's own speed test, but their test can be a little wonky at times and the information given by the results is limited. They ask that you perform some speed tests at http://testmy.net. The following is the protocol for those tests...
Create an account at testmy.net if you haven't already. While signed into that account, and using a single device connected directly to the modem with a LAN cable, NO ROUTER, perform a batch of five download tests using the manual 12MB test size. Space each test at least five minutes apart. If possible, run a batch of tests a few times a day, preferably in the morning, afternoon and evening. If you can't do a batch during those times, that's okay. The important thing is to try to get some tests from different times to be able to tell when the slowdowns are happening and when they are not. This info helps them in determining what the problem could be.
After you've run some tests, post your Results page URL so the tests can be looked at. While signed in at testmy.net click on "Results". Then, while on your Results page, copy the URL and paste it into a post on here. It will look like the link below, but with your testmy account user name where it says yourusername.
The router must be eliminated during the tests as routers themselves can cause speed issues due to multiple reasons.
As I stated in the post, if you can't run them at the suggested times of the day, run them at other times. The important thing is to get some tests. Without the speed tests, the reps will have nothing to go on. For speed problems, this is the process.
Lastly, most often the Reps will reimburse you for running the speed tests. They can't give you any tokens right now as they aren't on, but will be back tomorrow around 8AM EST. If you don't have enough data to run some tests now, wait until tomorrow and they should give you some to run them. Either way, though, they are going to need some tests to help you.
Also, you can set the site to automate the five tests each time you do them. Set it like it is in the picture below, with Download selected, the size (12MB), how often (every five minutes) and number of times (five), and check the nfw box, then click Start Automatic Test. It will run the five tests on it's own. Make sure to be signed in to the account you create when running the tests, too.
I can understand the frustration. It not that anyone is blaming the router, it's just that it can cause problems with getting a baseline speed. It's eliminated in case it is, which sometimes it is. Is yours? I have no idea, and neither do they, at this point.
Again, you don't have to run the tests at those times mentioned. If you can only run some tests in the evening, then do that. It's not that they don't believe someone when they say they are getting slow speeds, it's just that they have to have some info to go off of, and speed tests give them that info. The tests at testmy.net also give them a LOT more info than just the speed alone, which can help them in determining what is causing the problem.
Again, I understand your frustration.
Also, and this is just my opinion, from now on I would deal with the official reps on here. They are at the corporate level in Maryland, not at a cubicle somewhere in the Philippines. They have more tools available to them, including access to the engineers, when a problem needs to be fixed. They also have a LOT more knowledge than the phone reps. And again, this is my opinion, but they can help you MUCH better than the phone reps. The only drawback is that they are only on here from about 8AM to 5PM EST M-F, not 24/7 like the online reps. With that said, I'm sure a rep will reply tomorrow.
While you have alluded several times to having your plan changed without your knowledge or authorization you have never provided any details as to when this occurred and changed from "what" to "to".