Poor service and false advertising

I bought a Samsung Galaxy J7 Prime in October, when I bought it was written that it is a dual SIM. Today I went to Foschini kuruman telling them that my phone cannot another SIM card as it was indicated when I bought it. I was assisted by Linda was very rude, she did not even want to listen to me , she was saying I am lying that phone is not a dual SIM, I requested that we go and check on their display, after she initially refused she eventually agreed even today that information is still displayed that it is Dual SIM. She called Leandre who is her supervisor , she was also rude did not even want to listen to me, busy taking Linda's side. The least they could have done, it was to confirm from they cellphone provider whether it is a Dual SIM or not and then apologised to me for false advertising they made a scene accusing me of being a list in front of everyone. I have been a Fischini customer for years and I have been all my phones there, that kind of service and rudeness to customers is not acceptable . Finally I was busy talking to them in English and they were busy with Afrikaans even though I tell them O don't know Afrikaans, English is an official language is South Africa they must also to talk English.