INT Transaction Can't be reversed wait 14 days

An unauthorized deduction of R 340.43 went off my account int transaction but i didn't purchase anything when i phoned Capitec thei're solution was to cancel my card get a new one go to the branch i can understand that to a certain extent but they could not reverse as it sas a card transaction i didn't purchase anything it will take 14 days to investigate now what if that R 340 was almost the only amount left in my bank account for example would saying that make a difference as i barely make it with the existing amount but my bank can't sort this out and it will cost me R 70 if the were to pay it back that i will accept as i still get most of my money back