Got a new phone on upgrade but didnt enjoy it want

I went to go upgrade at tiekams audio video vodacom branch at Queentown Pick and Pay mall. Firstly the service was poor and she was not helpfull. I chose my phone and when i got home and tried it out - i hated it. It had half the memory my old phone use to have and was so slow. I called the very next day to return it because they do have a 7day return policy but the lady did not want to take it back because it was a slow seller and it was not her fault i chose the wrong phone. I am highly disgusted with her attitude and when i started to tell her about how bad the service was she hung up in my ear!