Thank you for contacting me, I'll gladly assist you to the best of my abilities.
Your account was suspended due to Riot Point purchases that have been charged back. This means that the owner of the credit card which was used to purchase Riot Points on your account has reported the charges as fraudulent, and subsequently, received the money back after the Riot Points were already spent. Your account is now considered to have negative balance.
By this time, you should have received an E-mail explaining the reason for this suspension and how to obtain your account back. This would include instructions on how to return the funds that were charged back through Paypal.
If you have not received this email, please contact me, and I’ll be happy to resubmit the message to you.
Please let me know if you have any other questions.
Work hard, Play Harder!!
Warmest Regards,
Levis Bjork
Riot Games Player Support Specialist