Ting Shao has been a great support to me.

During firmware upgrade, I messed up my S3 Controller board.  Ting Shao replied and asked me to send it for RMA.

I said it will take 2 weeks to get to China, and I prefer to pay upfront than to wait for the RMA fix.   

I paid for the S3 board (since it was my f***up), the board showed up 2 days after via UPS express.

Bitmain's customer support is excellent.  I think if you are reasonable with them and don't try to hide your f***ups and try to scam bitmain, you will get your fix right away.