Vodacom very bad service

I am a vodacom client for many years I returned two devices within the cooling off period but Vodacom kept debiting my account for the devices. Ive called in over 50 times to get my refund. Ive been trying unsuccessfully being pushed from one department to the next. When i ask to speak to a supervisor or team leader they refuse. I demanda full refund for all monies and also someone responsible from vodacom to contact me.