Mevrou & Co. - from smart & witty to low quality

In 2018 I bought a t-shirt from Mevrou & Co. I was very satisfied with the purchase as the material was good quality and true to size. Now I bought more t-shirts with the same size. However, the sizes are oversized and definitely not the same quality. I am very disappointed with my purchase and want to return the items. I have contacted Mevrou & Co. twice to arrange the return as per their website, but they have not responded to date. And there is no phone number listed to contact them. How am I suppose to return my items. What an unsatisfying and disappointing experience.