I have bought Ghost Recon breakpoint add ons but the game is the same I want the refund.
And I cannot see the refund button in the payment history for that game
If the Request Refund button is not present, then the item that you purchased is not eligible for a refund. If you believe that the item should be refunded, please contact Customer Support by visiting support.google.com/stadia.
Voluntary Google Refund for Games
I have been already here support.google.com/stadia and here https://support.google.com/stadia/answer/9598538?hl=en-GB and the only way to contact stadia support are twitter, facebook and this community.
I have tried to contact them on facebook and no aswer and here you are suggesting to go back there.
Do you know another way to be in contact with them?
Did you try to engage support via the chat feature? I found the folks on there very helpful? Open any support article, and you should see a contact us button in the upper right hand corner, if you click that a dropdown should appear that has a link to the chat service.
Chat and Phone support is very limited currently due to the pandemic, that is explained on the support website iirc. I would suggest patience with the other options available given the current unusual circumstances.
Since this is a community forum there is pretty much nothing that we can do to resolve account and payment issues such as refunds for example.