GBG Residency: Unexpected charges affecting returns?

Possession was in March for my GBG Residency flat, and honestly things nobody told me are surfacing. Builder ne maintenance ka jo bola tha, RWA usse zyada demand kar rahi hai. Unexpected charges se mera projected rental yield hit ho raha hai. Investor hu, ROI ka tension hai. Anyone else facing these hidden charges post-possession here? Kaise manage kar rahe ho to protect your returns?