Premium hike without consultation

Discovery health can’t be contact via their call centre. I have left a review early last week and my elderly parents were comtacted by an agent Supporting documents were required and sent Following that discovery went ahead and tried to debit my dads account for the higher premium The only notification sent to my dad was a sms stating that their plan was upgraded without their knowledge It’s very upsetting that big companies try to take advantage of the elderly and those that are not tech savoy