Overcharge on debit order

I am on a price lock package for R749 that I took last year in December 2018. This month DSTV decided to charge me R957!!!! Taking money out of my account that was NOT agreed on. I have been calling since Mon 2 September and all you ever get told is the query is been escalated. Every number and email for the price lock department does not wor****! I am still waiting for someone to call me and rectify this and I want a refund for the extra money that they took without my permission. I am so fed up and frustrated with their shocking pathetic service and trying to get someone to assist me.how do they have to right to just debit money out of my account as they please??

No one has called me this entire week to rectify this.