Still waiting on my refund

I'm so sad to be writing this. I had such high hopes for this company. I ordered 2 swimming costumes in October 2021. Delivery came late November and unfortunately one was too big and one was damaged. I returned one to swop for a smaller size and requested a refund on the other. All my dealings were friendly and efficient with the team. They responded quickly and were very friendly. Except in trying to claim my refund. Despite numerous requests and numerous promises that it would be done, I am still waiting nearly 3 months later. And not a word is said to me on the refund. I am so frustrated. This was so avoidable. And now they have not only lost a return customer, but I am now vehemently warning people about dealing with them. All parts of a company's service need to be top class, or it all falls to pieces.