Account debited Four times

I app**** for RCP in January; during the application we made the agreement with the bank that when I start paying they should debit my account on the 25th every month; in January and February my account wasn't debited; in March standard bank called me saying that my account was in arrears; I made an arrangement with them to pay for January and February on the 24 on March n they payment of March will go through on the set date 25th; they deducted my account Three times on the 24 and once on the 26 of March; they made four deductions instead of three; since 28 March I have been going up and down to the different but end up failing to get my refund; I called them also n get many references but my issue wasnt resolved.