Size 9

A friend of mine ordered and paid for a Nike Air force 1 Low black with rope sneaker size 9 UK. On 07/12/2022 the sneaker was delivered but the size was not correct (8.5 UK) . I would like to arrange an exchange. We have been trying to get communication with the company but no luck. Tried Email and social media but no response. Could someone advise on how to get in contact with the above mentioned company?