Flipkart Internet Private Limited - Lower model computer delivered

I purchased lenovo aio *** touchscreen model from flipkart via seller named Consulting rooms pvt ltd. The listing of the product mentioned model number *** touchscreen but seller delivered *** model which is very outdated. I asked for replacement and seller again sent the same old model. I refused to take delivery of replacement and called cust care of flipkart to return product as seller keeps sending low cost different model for this order. Cust care said they cannot take item back and only replacement can be done. I said im ok with replacement if model is what is listed. This happened on **th oct and now they saying theh will replace item on **th oct. Why do i have to wait for sellers fault? I need refund as i want to purchase the item for my new office. This is ridiculous rrom flipkart and the seller.