N11 Sent Me an Opened Product and Did Not Give Me a Full Refund

I bought a product from n11.com. The company sent an opened product. I started a return process on the grounds that an opened product was sent. My return was accepted. However, n11.com does not make my full refund by putting forward meaningless excuses. It made a refund lower than the amount I paid. This is pure deception. I contacted customer service through the website and the representative was not helpful at all and was disrespectful. It says to rate the service you received as if it is making fun of you, whatever system they have created does not allow you to give a negative score. I have been a customer of N11 for years, I have been subjected to very unfair practices, I have been victimized many times, but this is the first time it has not returned the money it took in full. If you do not resolve this victimization, I will cancel my membership, it is nothing but disgrace.