It seems none of the furniture or white goods shops open on a Sunday. We have used Eren Spot lots of times to buy things, but also have shopped around. There is an excellent shop opposite Eren Spot it's on the corner down to the left (away from the market) They have three floors of furniture and white goods. We have bought from them and found them excellent, we also bartered prices down.
There is also a Beko Shop in the one way street which runs parellel to the street Eren Spot is in. It's almost back to back with Eren Spot. We recently bought all our white goods there including a freezer.