Unauthorised debit following cancellation

Monthly fees increased from R99 to R427 without warning or explanation. Call centre unhelpful and usually don't even pick up. When they did I was told to email [Email Removed] which I have done repeatedly. After 17 days I got a reply from an 'agent13' at a different email address and was told that it would cost me R1313.52 to cancel my contract. No explanation as to how this figure was calculated and still no explanation re the more than four-fold increase in my monthly fees. Subsequent emails to both email addresses go unanswered. Intend to contact friend at the Daily Herald.