Replacement for LG 75NANO916 Television Delayed and of Lower Quality Offered

I purchased an LG 75NANO916 TV, which had light leaks, and the service approved a replacement. However, Antares Teknosa, where I bought the TV, does not have the product in stock, and they are suggesting a refund or paying the difference to buy a lower-quality TV. The LG service called me and offered a TV75QMED7SAQA model, which is a lower-segment TV than the one I bought. Güneş Elektronik called me and said that my 75NANO916 model is coming into stock in March, but Antares Teknosa is not offering me this option. I demand that my problem be solved urgently with a replacement of my product as my consumer right in accordance with the Turkish Code of Obligations No. 6098.