Gaursons possession delay — what's the scene with other builders?

Honestly not sure what to trust anymore. We booked a 3BHK with Gaursons in Noida Extension about three years back, thinking kids ke school admission tak mil jayega. Abhi tak possession ka kuch pata nahi. Unka customer support toh phone bhi nahi uthata. Builders jaise ATS ya Godrej Properties ka delivery track record kaisa hai? Yaar, yeh project delays kitna common hai? Aur baad mein maintenance charges kya kya aate hain? I'm worried about hidden costs too.