Well in cases like this there is no need to be cautious. The dealer is supposedly reputable and so is the brand...yet it appears they fobbed you off.
Even the village idiot could see that this product is defective. Lets hope they do not try to sell this to the next poor unsuspecting person.
Serves as a warning to others! I like the retailers return policy..."
Our Guarantee..we want you to be 100% satisfied with your purchase"! 
Obviously nice words that mean little not that that is any comfort to you.
Depending upon where you are try to go to a shop like Bintel. At least they have fllor stock you can touch and fully support their products.