Returning of goods.

Recently bought a phone at Pep Home, Blue Hills. I wanted to return it the following day since I noticed it wasn't 4G supported. I was told I cannot return the goods and top-up to get one that is 4G supported unless faulty, even so they'd give me back the same phone. All this within 7 days of purchase. I feel my rights are being violated as a consumer, that I cannot return goods I'm not satisfied with.