CoNguyet: Less than half an hour later, GOG sent me an email, saying that they can offer me a gog wallet refund.
Most likely an automated message based on the type of problem you selected in the contact form. I got one after 30-ish minutes saying the considered the matter resolved, because I reported a type of problem that they'd worked on days prior, and I had to reply to keep the ticket open. I got another automated message days later, urging me to close the ticket by replying with #solved. I only got a response from a real person 5 weeks after I submitted my support request. One of the two problems is still not resolved and the last reply I received was on Friday.
Long story short, buckle up for a long wait.