Charge for Reservation Changes on Spacia X

Has anyone done a reservation change on Spacia X, for instance changing seat assignment or departure time and were you charged for the change?

I booked a couple of Cockpit Lounge tickets to be used on January 5 for Spacia X from Tobu Nikko to Asakusa — in case anyone is wondering tickets go on sale at exactly 9am Japan time and are sold out within minutes, I had a slight error in my initial card details and was delayed by 2 minutes and lost my initial seat selection, luckily I was able to snag the last 2 cockpit lounge seats.

For the return trip I initially selected a couple of regular seats but after confirming and paying I decided I wanted to sit on the side near Tokyo Skytree so I can take some photos from the train. I went the section of the Tobu website that specifically indicated a Ride Change. I selected my old seats, and then my replacement ones and reconfirmed everything. They again asked for my credit card details but I thought that was only for confirmation purposes. To my surprise I received a text from my bank saying I was charged full price tickets for the change in seats. When I check my reservations on the website it only shows the one ticket with the new seat numbers along with a tagging for “Ride Change”.

Do you really have to pay full charge tickets when changing seat reservations? Or is this an error on their part? I’ve contacted Tobu via a note on their feedback page but haven’t gotten a response.