The worse accounts department they will stress you until you are depressed

I have had the worse year 2020 dealing with spark account department, the whole year they kept sending me emails claiming that I'm not paying my account when they where in-fact successfully debiting my account every month, I couldn't get anyone on the phone and email to explain what was happening until now in Jan when I was told that they've been short debiting my account now they want me to pay what ever they've mistakenly didn't debit last year cause they were confusing my account with some other child's account who's in primary, no apology from them, and who's fault was it