H&m — Offer not given and points not added to my member id

Hi, I made a purchase in H&M for 30000. Since it was my first purchase I was supposed to get 10% discount which I didn’t get, I learnt about this offer later, not while making the purchase. Also the points, nearly 600, was added to some other membership id and not to mine. Sent many mails and called the h&m customer care but nothing worked. Kindly help me.