Fail to refund me within few minutes

Good day I have bought a ****le from Vodacom at Springs Avenues, less than 10minutes I realised that I bought a wrong one I went back to the shop explained that I made a mistake and ask for a refund since I was not using Vodacom as my service provider the lady helping me called the supervisor explain to her in Afrikaans then superviser came to me and said sorry no refund I explained that I just bought the doungle and still sealed with a til slip she said no refund and advice to exchange to airtime I told her I'm using other network but she refused to refund me and during the process of buying I was never informed that the is no refund please help .<br> <br> I believe that was a terrible customer service<br> <br> thank you<br>