Disappointing quality of services !!!! I was 2 day...

Disappointing quality of services !!!! I was 2 days ago in the showroom to buy from Evomag a samsung s8 and I specified that I necessarily want single sim. I pay the product in full, then I receive the dual sim version and I am forced to return it, after which I am told that I have to wait 2 days for the single sim to arrive because it is actually out of stock. OK, I wait and after 2 days I get a message to go pick up the product. When I get to the place I notice that the product that I give the people there is still dual sim! If I do not check to understand that they give me what they want ???
And with the money blocked a week !!!
How is that possible ??? If I placed the order and made it clear what I want, why put another product on my neck?