Moglix — Defective shoe

Address:

Millwright campus, 162 athippalayam road, Cinnavedampatti, Coimbatore 641049

I have bought a pair of shoes .
Order I'd 3451778
On wearing and walking I felt discomfort and my right heel got injured because of a projecting tiny nail .it's a manufacturing defect.
On complaining, your customer care rejected to take it back since I walked with this shoes.
Without walking how could I come to know the defect. Because it is a very small nail which is not visible.
But it injured my heel..