Nedbank send imali

i did the nedbank send imali on the 22 of March 2018 . i accidentally put the wrong number i realised my mistake . i proceeded to call nedbank to ask them if they can they reverse the payment they told me that i can't as they wont be able to trace it and i will have to wait for 7 days to get my money back . i mean why must i wait that long they told me its either that or i must call the person to check and see if he will withdraw the money. That is not fair other banks can reverse the payment why can't nedbank to that . why does it take so long for money to be reversed i mean nedbank is such a big organisation but they cant help their customers . i am really really dissapointed by this .