Hello, thank you for pointing this out, I will pass it along! For now, please do not use this until it is fixed. I would suggest creating a CS ticket if you do not like the reward of Guren.

https://support-center.oasgames.com/

I advise to send that to CS, so they can have a direct record of your account, and the number of times you have pulled, etc. I will be asking in regards for compensation as well.