Take a Lot bullying me to accept an unwanted phone

I bought a dual sim phone. A single sim card phone was sent to me. I returned it. It was accepted. Without a word, the same phone was returned to me with a box full of warnings, e.g. I must check the product before opening it. However, I couldn't have checked without opening. I was also confident that it would be the correct phone. However, after I had opened it, I discovered that it was the same single sim phone. Then I returned it again. Now, I am being referred to warnings on the box. I'm being sent the pictures of the sim card tray. It is being explained to me that the sim card tray is dual. Yet when I returned it the first time, they didn't go an extra mile to explain this new "dual sim card" concept of theirs. I feel like I had been trapped into opening the box so I could be bul**** later. Now I am told that whether I like it or not, they are going to send the same phone to me and I have to accept it in spite of telling them that I don't want this product. This is not fair, esp because I have been a customer there for a while. Please stop the bullying.