Taking debit orders even though her account is manually paid

My mother was retrenched in April 2020 so i have been paying her account on her behalf on the 25th / 26th each month yet vodacom STILL deducts a debit order from her account meaning the debit bounces and she is charged R250 per failed transaction. We then moved the debit order to the 7th of the month so the money has more time to reflect, low and behold ANOTHER debit order was taken and returned. Vodacom has now caused my mom to incur almost 7 months of fees due to their incompetence. Now she is told to go to a shop to cancel the debit order?? Will not recommend to anyone!