BE CAREFUL!!

I purchased my mother a rain simcard using my rain account (which was due for paymenton the 1st of September), so I had to put in my mothers banking details in order for rain to debit the R299 for the simcard that she bought, which they debited on the 31st of August. Now rain also used my mothers banking details to pay my account without her concern....when I call and ask why it happened they can't even explain it themselves! HOW DO YOU DEBIT FROM SOMEONE'S ACCOUNT WITHOUT THEIR CONCERN?? I MEAN WE'VE ALREADY PAID FOR THE "NEW" SIMCARD!