My capitec account was debit without my concern

Hi,on the 1 November 2021 which it was on Monday around past 10 at night I receive an sms on my phone with a debit order of 249,when I check to my surprise that I realy dont know what was the debit for,and it has been debited without my permission.I tried to reverse the debit via app but it was not reversible ,so Tuesday morning I call the capitec toll number and explain my storie I was told to go straight to the branc,I went to the branch unfortunately I never get any help they just told me that the money it's not reversible So my concern it's my money was debited without my permission