Bad service

Hello Peter I have ordered Nike Dunk Low Retro men’s shoe size UK 10 online at *** the Date was 05 May 2024 .upon finding out that the size I ordered was small I returned it back and asked for a refund or an exchange then they sent an email on 23 May 2024 stating that I will see my refund very soon which I haven’t received till today and there’s no communication from them. Can you please help me