MTN is just Slow, and makes no sense

In April I requested an upgrade and canceled it, I spoke to Thabisa from retentions, she told me my account would not be debited at the end of May. My account was debited R1,015. I called and spoke to a guy called Tshepo Sikhakhane, 1- ********** 1506 he told me that the refund would take 14 working days. I didnt get any feedback called on the 11 June spoke to Andiswa, ref ********** 23 and she said she would call me today...Nothing. Now I am holding on the line and the guy says I will be refunded R800? why? He says for upgrade costs? which costs, I never got the device and noone told me about these costs all the times I have been calling, even he doesnt know why I was charged. Please assist.