Plot issue in block d , phase 8 , bahria town

I will try to keep my story short. I am a pakistani living abroad. I purchased in 2010 , a plot (1 kanal with additional land and all dues were paid ) in bahria town phase 8, block d, bahria town. Earlier this year, it was discovered that BT had sold my plot to someone illegally. Visited pakistan in february 2020 and contacted BT office. BT officials admitted their mistake and assured me that the matter would be resolved soon. Unfortunately, after a long time, my problem is still not solved. Any suggestion related to my issue.