Defected goods at a Marked up Price, branded as so called quality

Good day,

In the beginning of this year, we bought Facemasks at Identity in Westgate. Two weeks ago, the stitching on the one facemask unraveled (clearly this is a defected product being sold to the client).

The challenge is that we recently moved from the West Rand to the East Rand and we discarded the slip (if we knew that Identity sells such poor quality, defected clothing, and we needed the slip, we would have kept it, however we trusted Identity since you pay and arm and a leg for the clothing, so one would except some quality) We made a request on Facebook, at first it was we need the slip, we explained our situation (clearly the robots behind the FB account does not understand moving, and understand that you have faith in a brand/ company hence you don't keep the slip), then it was, no they cannot exchanged it.

In this case is where a product is defected, the stitching came lose, must we just take it on the chin and say okay Identity does not exchange is, we will bear the lost? If this is the case then I will pay up my account, and I will never buy from Identity again, as it is clear, that you guys are selling, defected goods at a marked up price, conning people to believe that this is quality.