How would I go about disputing a friends and family Internationally (got scammed for riot points)

[ben5z]

Months ago I paid for a service that would go on my account and buy me a currency for League of Legends (half off).
He had me send money as friends and family to an email that was in the Philippines.

I sent the money. Days went by and it was fine.

But, today I logged into my account on League of Legends and i was perma banned.

I talked to the support team, they confirm it was because of chargebacks. Here are some chat logs: https://pastebin.com/25YZLv5V

The guy who did the service fooled me, and I need information on how i would go about disputing.

Clearly I sent the money.

Here is a screenshot of the options inside the resolution center for the dispute.

I have not done anything but i am planning on emailing them before hand.

Screenshots of s

I have all of the skype chat logs. 

TLDR: Paid for a service to get half off of currency in a game (League of Legends), used FAF Internationally, got banned on the game, need help disputing.