Store manager didn't want us to change or return the phone after a day of purchase

My aunt (Anna Mosima Mothoa) bought a phone yesterday 06/10/2021 at Railway Furnishers at Jubilee Mall at Hammanskraal. My aunt called us to see the phone last night (06/10/2021), only to realize that it is a Nokia 2.4 and we heard many stories about Nokia freezing. Since we didn't want her to struggle, because she was going to use it for long time, we advised her to get another brand the following day. My sister (Christian) went with her today (07/10/2021) only to be told by the Manager (Rose Gololo) that the phone can't be changed as it is a second hand phone (Mind you the phone is still sealed, never switched on). How is it a second hand phone when it hasn't been used or switched on or even passed 7 days return? They took advantage of my aunt, because she is a pensioner and she was alone. Bear in mind we wanted to change the brand and they refused. We wanted to cancel the phone contract the refused. As a customer my aunt has a right to return the phone before 7 days.