Anyone else facing post-possession surprises?

Under-construction projects are a total headache, even after possession. VKG Group ka flat Sector 83 mein liya tha, possession March mein mila. Abhi 2 mahine hue hain, aur society maintenance charges double kar diye bina notice. Brochure mein kuch aur tha, ab yeh naya scene hai. Builder ne bola tha sab clear hai, but ab extra charges maang rahe. Koi aur bhi yeh experience kar raha hai?