Lenovo — service delayed for lenovo k4 note - imei no.[protected]

Address:

Kolkata, West Bengal, 700070

I have given my mobile handset for repair to lenovo service center (Hcl kolkata - 700072) on 25.07.2017, but after 23 days part they don't repaired the same and not providing any information. I complained to the lenovo also, they not providing any information and buying time.
I have also escalated the matter, but they are not reverting.
They are acting like a local manufacturer and cheating the customer