Discovery my worst nightmare

Since I joined Discovery it has been nothing but a nightmare. I called the call centre early December to ask if I can pay my monthly premium of R2085 a week earlier than usual since companies pay salaries early, I was reassured I will not be debited. I paid my medical aid on the 17th of December 2019(POP has been sent to discovery), to my surprise I was still debited on the 27th of December, I then reversed the payment. January the 25th 2020 I was double debited R4170 and when I called to inquire I was told because they cant see my December premium. I have provided them with all the necessary documents they requested from me, Iv called their customer service everyday and even sent emails and they still have not refunded me my one months premium and they keep telling me they will look into it.