Vodacom Contract Complaint.

I took a contract phone from vodacom last year late. 1st and foremost when their their debit only go off on the 1st or the second when I clearly told them that I need it done at the end of of every month, not beginning of it. Now for the past 3 months they haven't been any debit on my account from vodacom, today is the 3rd and no debit has gone through from them, and then mid month they'll be sending me threatening msg's to put me on credit bureau, and the interest that now I suddenly have to pay for their own mistake. When I called the center yesterday I spoke to the mechine due to Covid19 which is understandable but which means I might find myself paying another interest again. Can Vodacom kindly fix this please, we are already suffering financially as it is, I don't need this drama. Thank you.