I spent a lot of time contacting customer service, and their customer service was very segmented, so I was directed to different service links.

This took me a lot of time.

The final answer I got was that they don't provide support for third-party platforms.

I had a problem buying their company's games. Steam asked me to go to Square enix, and Square enix asked me to go to Steam customer service.

This is a terrible way to handle this. There is no guarantee at all when purchasing a game.