Really hoping my country doesn't follow suit to this. I can get a seat in a nice cinema with big seats that can become a bed with a push of the button for only 10 usd (which includes free popcorn!). Did you perhaps pay using a Credit Card? From my experience every time I buy stuff online like bus tickets which you usually buy at their booth, I have to pay extra for the "convenience".
For credit cards, companies sometimes charge a 2.xx% convenience fee because credit card companies take a 2.xx% cut, leaving them with only ~98% of what you paid them. But yeah, $6 convenience fee for a ~$55 purchase is absurd.