N11 Order Delayed for Over a Month

I purchased an item from the N11 store on January 20th, and it still hasn't arrived (today is March 6th). Despite my repeated attempts to cancel, I've been told that the item cannot be canceled because it's already in transit. Today, they called me, saying they needed to cancel the order because they couldn't procure the item. To make matters worse, the same item from the same seller is still available for sale! I bought the item for ₺1300, but now they've raised the price to ₺2100 and are refusing to deliver it. What's worse, N11 seems to be on the seller's side. It's not about the customer...