Telkom Mobile refuses to exchage bought less than 24hrs ago

My wife lost her phone through smash and grab a week ago and I wanted to surprise her with a new phone. I took out a contract for an A71 yesterday 04/11/2020 from Telkom mobile Fourways. Unfortunately the phone is too big for my wife, the screen size is too big and not easy to handle. I tried this morning to exchange the handset for her but was told there are no exchanges and nothing can be done about it. I have been a client of Telkom for many years even the phone she lost was a comtract phone but feel very disappointed that I cannot be assisted in this regard. 24 months paying for a phone you are not happy with is very long and painful. Kindly look into this matter and assist. It would be very sad if Telkom offered no assistance or possible way through this situation.

Regards Brian Masenda