HughesNet overcharges me $355 and offers only a $60 credit when admitting to it

Beginning in January of 2018, HughesNet offered me a Gen5 spped internet if I signed another contract for 12 months, at $30 off and they were to waive the one time fee of $175, based on previous mistakes. HughesNet failed to follow through with the promotion, and charged me this fee, along with increased monthly charges, totaling $355. When I spoke to their office overseas in India they stated that they were not willing to credit me more than $60 credit to the account (not even my money back) because I did not catch it in time. They looked at the notes on the account and saw on Feb 21st that there was a promotional code and that the $175 fee was not supposed to be charged. She said the rep failed to insert the promotional code and that was why I was charged. They took my money, and won't offer to fix the problem, and insulted me with a $60 credit.