Noida Ext flat: Quality issues and high maintenance, am I alone?

Construction quality is a total gamble, that's what I've learned after moving in. My 2BHK in Sector 137 ka possession March mein mila, aur I'm already seeing plaster cracks. Bathrooms mein seepage ka issue bhi start ho gaya hai, which is crazy for a new flat. Builder ne jo finish dikhaya tha brochure mein, woh bilkul alag hai. On top of that, maintenance charges ₹4.5/sqft le rahe hain, which feels like extortion, yaar. I thought Godrej ya ATS jaise bade builders reliable honge, but my first-hand experience is kinda disappointing. Things nobody told me before booking. Has anyone else faced similar quality issues with their new flats in Noida Ext, especially from builders like Gaursons or ACE Group? Kya yeh sab common hai, ya I just got unlucky with my unit? How do you deal with these post-possession problems?