frequent visit to macau

I'm holding a valid singaporean passport and I travel to macau very often example once every month and would at least stay for 2 weeks before returning back to singapore for a week or so then back to macau for 2-3 weeks as i enjoy gambling there. However most of my visits will be stop by the immigration claiming they would only give me 10 days or 20 days. Is there any way that I can apply for a frequent visitor or something that would solve my situation?