DEFECTIVE PRODUCT RETURNED BUT DENIED REPLACEMENT FROM STORE

Pls note I had purchased a sports wear (ARM Gaurd) from NIKE Showroom (SSIPL Retain limited, Shop no -102, 1st Floor, Premises No. 164/1 Maniktala Main road, Kolkata -54, WB, on the 17th April 2015. The product
did not even last for 10 days, it started tearing off & all the stitches were coming off. Since it was a defective product I had taken to the same shop for replacement on the 25th April 2015. The store manager & staff assured me that is was goig to take atleast 7-10 business days for the replacement to come. But till today i call them up, i get to hear that the product has not yet come up & they do not have any timeline as to when it will reach.
It has been more than 20 days that the product was sent for replacement. And the Store staffs also do not assist nor they have courtesy to apologies for the same, rather they argue & talk top of their voice. Is
this customer Service? Is this how to treat a customer? Im very unhappy with NIKE.