Rain debited my account without permission

Rain provide me with wifi and i pay 499 on the 25th of each month, they debited more than 1000 from my bank account and now they taking me from pillar to post for my money to be reversed back ive escalated with Absa which is my bank ive send email to debit card disputes and *** za they asked me to send letter from rain saying there were not supposed to debit money and rain is giving me problem am frustrated and they still trying to debit money again and i dont owe them anything they disconnected their services can i please get help