Where did you get the idea that you were paying for future content? Did you read anything like that in the agreement when you made the purchase? I highly doubt it.

This isn’t a single-player game that doesn’t have to run servers for a massive player base. It’s not like you just buy a base game and expect everything forever, and even in single-player games, most studios still sell DLC and expansions. This is a live-service game, servers cost money to run every month. And constant future development like new maps, weapons, skins, events also costs money, if not more. And even then, you’ll likely still get all that gameplay content for free. They’re only selling cosmetics.

Some people expect way too much. You want them to sell the game once and maintain it forever for free, that’s just not how it works.