RETURN PHONE FOR MY MONEY

I recently bought a phone Huwaie Smart on the 20/02/2019. Today it's the 24/02/2019 I tried to return the phone back for my money back and only to be told I cannot return the phone is faulty, of which it is not. When I bought the phone I was under the impression that it's dual and only to learn it is not. The phone has no technical problems, but I'm just not happy with the product and fail to understand when I was told at MTN that I can not return the phone for my money back as that was not explained to me at the time of purchase.

The terms and condition according to the 7days rule is what was explained to myself and I want to think they are confusion the two matters. To cut the story short I would like your assistance to return the phone with my full cash return, as I bought it cash, and has been in my possession for 5days. I was not happy with the service, especially from their team leader who has no. Way of handling customers.