Vastu Vihar — Company not handing over flats

This is in regards to complaint ID: 2156264 which i raised on 25 Nov 2018.
Vastu Vihar team in Deoghar, Jharkhand is not handing over 2 flats booked in the name of my parents.
2 nano flat on first floor of last building was booked in 2013 and 2014 north east and north west location.
They also assigned my flat to someone else after numbering the flat on their own.
In my last complaint the company assigned a person to settle the issue in 2018. After 4 days of frustration he told us that they have solved the issue and the flat will be handed over to us after completion.
On 31st August 2020 we called the project manager of the Deoghar site that we want to take over the Custody of flat on durga puja.
Now they are saying that the other party has filed a court case and hence the flat will not be handed over till the case result is not declared.
When we talked to the company lawyer he tries to convince us in taking another flat and created the same scenario as they did in 2018.
As per our understanding they are trying to take our flat by hook or crook and sell the flats on higher rate to other customers.
It has been 6 years and 7 years and the flat has not been handed over to us.
We are desperately seeking for help.
My parents are old and i fear this issue created by vastu Vihar team will lead to my parents depression.