twinklepa
Are the sale prices listed for new subscribers only? If so, it might be that the representative was offering the sale price to you, an existing customer, but only for six months.
You can check what plans are available to you by signing into the HughesNet MyAccount site, then hovering your pointer over Shop/Upgrade and clicking on Plans & Pricing. There you should be able to see the plans available to you, and then the prices when you click on the particular plan, including any sale prices. You can also change your plan there if you choose to go with a different one by adding the new chosen plan option to your cart and completing the transaction. Any prorated charges or credits will then appear on your next bill.
Edit: I should add that I don't know if what is said above is the case regarding the six months. I only mention it as a possibility.