Complaint about appolling customer service by absa

I am absolutely appolled by Abasa bank after being a loyal client for more than 40 years. In 2020 I settled an overdraft with absa of about R48000 and requested them to close the account as I was moving into my pension. When my pension was paid out and I subsequently made my transactions for a purchase of a new property, I later realized in 2021 that the initial overdraft had not been closed and I had incurred another R60000 on it When absa notified me I made arrangements that I will pay it in installments of R500 until I have settled, futher if I inherit any capital I will contribute it to the overdraft to bring the balance down. This year absa decides to unilaterally deduct amounts of R4000 from my account breaching the initial agreement. This is not only ********* but ******** and unbecoming of a bank that purports to be acting in its clients interests. I'd like an immediate investigation to this and like to caution the public to be weary in doing business with absa going forward.