[Sᴛᴀɴᴅᴀʀᴅ]

As the title suggests, or have they changed their system?

[JuStBenZiN]

They actually do, but they usually instantly ban your account before you even have the chance to talk to them.

[NA Riven]

No they dont its ok to cb a big company

[xShadowAlk]

No they dont its ok to cb a big company

Can confirm.
Source: I personally charged back $300 and riot didn't even care. I got to keep all my skins as well.

[SUI-3183372]

Dumb friend just lost a $1,000 account for charging back $450 over the last 2 weeks.
Riot's response was that they'd unban the account if he repaid the full amount. He asked if they offered payment plans and they said no, that he needed to pay the $450 back in full or the account will remain banned.

[Λlex]

They don't respond directly to the chargeback, but they usually ban your account. I've had a friend that disputed $400 and when he asked them about unbanning the account, the answer was the same as the user above. Pay in full and get it back, else no. So don't risk it. You can do it if they ban you though.