Very Dissapointed with HOUSE & HOME

I am very disappointed with House & Home the way I was treated. I went to the shop on Friday 01/06/2018 at the East gate mall to purchase DSTV Explore together with the multi switch instead I was given LNB smart and I ask the salesman if it is going to work and he insisted that is going to work. Remember I am customer I don't have much knowledge compared to the salesman as he deals with this kind of stuff everyday. I got to my place to connect the DSTV as I open the boxes I found that it is the wrong switch. I went back to the shop on Monday 04/06/2018. when I got there the security lady completed return slip for me and advised me to go to the cashiers, the cashier recognized me from Friday and she was very sympathetic because she witnessed the part that i kept asking the salesman if it was the correct switch and she told me not worry the manager Elize will give me the refund. To my surprise Elize did not even want to know my story she told me she cant help me because i opened the box. I am asking myself for me to know it is the correct purchase didn't I suppose to open the box? because their salesman definitely doesn't know what he was selling to me. Elize told me I should take up the matter with the salesman not House & Home. I am still confused whether to go to the nearest police station to open a case of been ill advised on a purchase or go back and wait for the salesman to knock off maybe he will give me my money back. I don't know what I should do, I very much dissapointed