I tried both methods described to instal Balder's gate (gog galaxy and individual setup) and the game is not installed. The support bot is useless and I don't Know how to contact gog to get a refund or a solution. Please help!

Hello,
If you click on the name at the top of the website and then on the dropdown you click on orders and settings it should list all your purchases. Find the game and if the game is less than 30 days since you purchased right on the card will be an option to return the game.