Money paid. No product. Poor service. Terrible communication

I am so horribly disappointed in the service I have received from Adidas online. I ordered grey training tights on the 9 January, my order was delivered on time, great, but it was the wrong colour. Black instead of grey. Mistakes happen, that's fine. I emailed on the same day of delivery that I had received the wrong item. No response on this email. I called and the operator said I must send a picture so they could log a return. I did this, still response from them after I had sent an email with the picture. Again, I had to make the call to follow up. Only then was the return logged. The email received after they had logged the return said that the item they delivered would be collected from me and returned to their warehouse within 4 days. 4 days later, that same wrong item has not been collected from me for exchange for a mistake that they had made. Worst part is when I check online, the item I had ordered is no longer available in the size I ordered it in.