Failure to terminate

I find Fedhealths customer service very poor and inefficient. I have been a customer of Fedhealth for over 6 years. I needed to change my medical aid when I got married, I was instructed by Fedhealth that I needed to submit 1 months written notice of termination in order to terminate my medical aid. I submited my notice of termination in November 2018 for End December 2018. I sent a second email on the 12th of December to confirm and was told that my medical aid still hadn't been terminated. After a 30 minute phone call to them on the 3rd of January I was assured that my termination will be handled. After another 30 minute phone call of the 15th of January my medical aid has still not been terminated. This is frustrating, I dont know what else to do. But without a doubt they will debit their monthly fee at the end of January for a service I have been trying for 2 months to terminate.