Expensive faulty clothing topped with no service

I recently acquired Polo gholf shirts at over R1000 each for work and not even 3 months down the line the armpits are totally destroyed. Definitely a material flaw as confirmed by the store that I bought it from. I handed it back to the store who promised me an answer, this was 4 weeks ago, Polo even came and fetched the goods and disappeared. I will not buy this brand again.