Just like the title says, I've been asking for a refund for 3 days.

The only reason I bought this game was for the italian translation, which was listed as "audio + subtitles".
The reason I'm asking a refund is because the description is wrong and I didn't get what I paid for: there's no italian audio on the game.

What can I do?

Wait. It's all you can do. Seems to be a clear cut case, and you should receive your refund. I wouldn't expect GOG to process your ticket before next week at this point. You can also double check your spam folders for any GOG emails.

Thanks for your reply, I will wait :)