N11 Has Not Refunded My Returned Product After I Changed My Credit Card

I returned a N11 buy item, but since the credit card I used at the time of purchase was canceled, I had to pick a new card. I have not received the money back in my account even though the legal period for a refund has passed. Several times, I told N11 customer support about the alteration in my card; they have yet to fix the problem. The lack of action on their side has made me feel disappointed about this whole matter. The fact that such a simple procedure has evolved into such a headache irritates me I truly expected better from N11 and hope they take quick care of this.