BrandsMart USA complaint: Scam practices

I purchased built in appliances from this company that were delivered 4 days ago. Salesman instructed me (multiple times) to open boxes and inspect product upon delivery, which we did while the driver was there. Shrink wrap was removed to look inside boxes. I called today to return product as our plans have changed and I m being told I will be charged 20% re-stock because we opened the boxes. I explained these were instructions from salesman and that the items were in their boxes exactly in the same place in my garage as their driver left them and the clerk informed me this didn’t matter that they would charge me anyway. Moreover their receipt says nothing about this. their return policy says nothing about this. I even contacted the salesman and he dismissed my inquiry referring me back to customer service as stating their open box policy.