Nissan Motors — No delivery for nissan magnite after 6 months from booking date

I have booked a nissan magnite on 20/02/2021 at nissan showroom in Kollam, kerala and the customer executive and manager promised me that the delivery will be at 4 to 6 weeks from booking date.It was for a marriage purpose.And the delivery failed in time and i contacted them again, they said delivery may take upto 6 months, it is sure that you will get the car within 6 months. I changed the marriage date.Now my marriage date is very close and when i contact the showroom they say no available vehicles is there for delivery. This is very difficult situation. All promises at booking time is failed...