Standard Bank system error gets me harassed daily by their staff

At the end of Feb this year Standard Bank failed to deduct a debit order on a personal loan I have with them. 2 or 3 days after 'all' my debits had gone off I spent some of the money from the account. Standard bank called to alert me that they did not deduct the debit and can they take all the money left in the account. I refused as that would have left me with 0. I arranged to pay R1000 that day and settle the remainder over 2 months.

On the Saturday I received another call and the person asking if they can take what is in the account. I explained that I spoke to someone and made arrangement to pay the remainder over 3 months...That was never done and this time the lady assisting did record the arrangement, I got the confirmation SMS and the debit went off at the end of March.

My issue is for the past 2 months I receive a call from Standard bank EVERYDAY asking me when I'm going to pay or if they can take what is left in the account...EVERYDAY including Saturdays I get a call to settle my debt They say the numbers are dialled automatically but surely an arrangement removes me from the list??

This is now harassment as I have made arrangements and honouring them by still get calls EVERYDAY