Harassment from Woolworths collections consultants

I am so emotionally drained, I am being harassed by Woolworths consultants. I arranged with the company to debit my account on the 15th of each and every month. Unfortunately, Woolworths did not stick to our agreement. I had to make a manual payment at the store. Last month I paid at the store the amount which was on the statement that was sent to me via email. Since last week I have been getting calls that my account is behind with R68. I advised the consultant that I was not well aware of that because I always pay the amount stated on my monthly account statement or an amount more than my installment. I advised him that I recently got my Sept statement and will make a payment no later than the 7th of November 2021. Despite the conversation that I had with the consultant I have been getting several phone calls harassing me as if my account is in arrears whereas it is not. I am really disappointed and disgusted by the treatment I’m getting from Woolworths. My account is not even on cycle due 1 and should not be part of collections. I am going to pay this account up to date and close it. I feel so emotionally drained.