Last night/morning, at about 4:30AM (Subeta time) I went through the offer link to sign up for Netflix, but still haven't received my credits over 12 hours later. ;M;

Unfortunately, this isn't something Subeta can take care of. The issue is on the sponsors end, and at this time, none of them offer a way for users to contact them with complaints. You can try to google the sponsor to get contact information, but there's no guarantee they will respond.