Gemini Enterprises — I have received a defective cylinder

Address:

Gemini Enterprises, Najafgarh Tehsil, New Delhi

I had booked a cylinder from gemini enterprises and i received the same within two days. However when I tried to fix it i found that the same is defective.
Further there is a cross mark on the cylinder which depicts that the cylinder is defective.
Therefore you are requested to submit my complaint and try to solve it at the earliest.
I have paid the full amount due for this cylinder.
Please exchange my cylinder Or refund my money