Nextra Teleservices — nextra go to hell

Address:

New Delhi, Delhi, 110019

From the past 3 week i am experiencing problem with my internet speed. I have complaint about it regularly but they are paying no heed to it. Even i have talked to the manager of nextra on customer number [protected], he said problem will be resolved within 12 hours but now it's the 21 days and the issue stand still.
Nextra customer id: 2067457 resistar mo. No. [protected]
Complaint no.:[protected]