Incredibly unstable ping on native server

I'm having the same problem (Singapore), I think quite a lot of people who play in Singapore server also have the same problem.

Rumor I heard is that because they can't find people (that are matching to your skills level or there isn't enough people in general) so that you're being sent somewhere to fill the lobby up to reduce the que time. But then again you say using VPN always gives you normal ping, then either is something wrong with their server, or they're changing something in their match making algorithm, I dunno (btw what's your Kill / death ratio?)