Discovery health *****s from pensioner

My 70 year old mother has been struggling with discovery health for at least 8 months or so.She was a client of theirs until she called and cancelled her cover with them as she could not afford it anymore.Her account has been debited with R1568 every month,even after she cancelled with them.She is a pensioner and that is more than half of her pension.This us unacceptable.She is disabled and now has to go through the hassle of going to a branch every month to dispute the debit as she cannot afford it.