NIIT — emailed about hard copies (marksheets) of my gniit but no one replies

Address:

New Delhi, Delhi, 110001

I had done gniit diploma from niit and asked for hard copies (Mark sheet) for my career requirement but till now didn't recv. I had given them the call however they responded quickly only for the sales lead when i told them about my issue they just ignored.

They are just ignoring my professional career and i think i have wasted my money by doing gniit.. I have emails which i wrote and nobody cares about.
Please let me know how can i file legal actions against them i have lot many people who have many complaints.

Reg: r[protected]