There is no reject all in GDPR, because functional cookies are still allowed. So the default behaviour is only functional cookies are allowed.
Edit: Companies have been fined for making cookie options too complicated, under GDPR all other cookies are opt-in. This is what a banner should look like:
GDPR infringements are categorized by severity and impact to its users, but also by the yearly turnover by said company. Meaning cookie banners by smaller companies are low priority.
You could try contacting the relevant Data Protection Authority from your country or the providers country.
https://www.edpb.europa.eu/about-edpb/about-edpb/members_en