Where can I find cheap, authentic, and certified lab-grown diamonds (LGDs) in Mumbai, Bihar or online in India?

LGD prices have crashed from ₹1 lakh to ₹50k (branded sellers still looting at this rate), then to ₹25k, and now ₹15k per carat with expectations of further decline as Chinese and Indian labs ramp up production at industrial scale. But most brands are stuck with old stock priced much higher and aren’t reducing prices quickly. I’m looking for trustworthy manufacturers or sellers offering LGDs at the newer, lower rates. Any recommendations?