H&m — I didn't receive refund money

I returned an item on 30 July and received an email from h&m that they have processed the refund in my account, I have been waiting for so many days now and I still haven't received any refund or any update on refund from the company, Im not liking the services, when I called the customer service no. They didn't receive, they didn't reply to my email, I demand instant refund in my account or.any update related to my refund