Warranty provision - replacement items

[haniede]

I am facing an interesting situation with a merchant - I bought an appliance in March that by end of May developed a minor malfunction. The appliance was obviously newly purchased and other than this malfunction was perfectly operational with no signs of wear and tear (two months of use). And to be fair, malfunction is totally cosmetic, it's an extra unnecessary feature for the machine to operate properly.

Nonetheless I decided to request a warranty repair. Shortly after the merchant informs me that the replacement product is being shipped. To my dismay, I find a replacement product with obvious signs of wear and tear and not my machine that I sent for repair.

Clearly I refused to accept and asked for either repair of my machine or replacement with another new, not used model. The merchant accepted to double check with supplier, and shortly after another, yet again different used model was sent. Obviously I have not accepted it.

What are my rights? Can supplier if unable to repair simply provide another used machine - surely in much worse condition that the machine originally sent for repair?