I'd register your disappoint with Hilton.

Hilton Customer Service Contact Form: https://help.hilton.com/s/contactsupport

Although I've seen a bunch of different chain franchise agreements over the years, I can't recall if credit card surcharges are permitted. If they aren't permitted, the hotel will get penalized for breaking the rules.

But even if it's allowed, your complaint will count against the hotel's annual customer service scores. (If an individual hotel gets too many complaints, they will get a visit from the Regional Manager for their region.)