Debited me 3 months ...

Debited me 3 months worth of payments for my Fibre service and only credited me for 1 month and when I complained I was told that it's my problem and that there is nothing they can do to reverse the transaction, asked to speak to a manager or supervisor instead consultant got a colleague to call me instead when I insisted on speaking to a manager was told he is on a call and never received the promised call back from a manager