I paid successfully, but there was no game, even no game order. Does anyone know what happened，I bought：The Witcher 3: Wild Hunt

Do you see your order here: https://www.gog.com/en/account/settings/orders ?

If not, I don't think the payment went thru.

But my money was actually paid to GOG and deducted from my account

You'll need to ask GOG:
https://support.gog.com/hc/en-us/requests/new?product=gog

Check your orders and settings and your mail, if you don't see a order, maybe the payment wasn't processed yet, it could take a couple of hours, if it's been more than a couple of hours try to contact one of the blues (https://www.gog.com/forum/general/recent_pattern_of_giveaways_contingent_on_bundled_mailing_list/page1) send them a message and they will help you.

Well, I sent it to them yesterday, and the only reply to my email is: We'd like to let you know that your ticket (# 1408977) is currently being processed, and one of us will get back to you as soon as possible
Please be aware that we are currently experiencing heavy support traffic, therefore response times are higher than usual.
We appreciate your patience and understanding.
In the meantime, we would welcome any additional information that you think might be helpful in investigating your request.

Thanks anyway All right, thank you

Try loading the refresh links in a new tab each, while logged into a web browser:
https://www.gog.com/account/refresh
https://www.gog.com/user/refresh

If you want to send a chat message to a staff member, you first need to change your privacy settings to allow chat messages from everyone:
https://www.gog.com/en/account/settings/privacy

It's set. Thank you

Something has been changed or is the first message still automatic and you need to respond with the same details as before, otherwise they will not proceed your ticket?