JKG Constructions delayed possession AGAIN! What to do?

Possession was promised in Dec 2025, now they're saying June 2026! I'm so frustrated. We booked a 3BHK in Block H. Kids' school admission depends on this. My wife's really stressed. Paid almost 80% of the amount already. Construction linked plan tha, isliye EMI bhi jaa rahi hai. They keep saying 'force majeure', but honestly I think it's mismanagement. Legal notice bhejna chahiye kya? Anyone else facing delays with JKG Constructions? Is it worth fighting this, or should I just cut my losses and try to sell? Thinking of shifting to ready-to-move, but scared of resale value. Koi idea hai kya?