"If you forget to cancel in that trial time-frame, there is still a full money-back guarantee for 30 days. This provides lots of time (risk-free) to decide if premium membership is right for you."
For assistance with the full-money-back guarantee, please leave us a ticket in support:
http://support.chess.com/Tickets/Submit
Hope that helps!
I wanted to take my money back after a 10 day trial but ı couldnt manage. they don't allow to take my money back. I can see 73 $ in my acount but. ı didn't find the way to take back