Membership suspended

My name is Lindiwe Twala. I joined Bonitas medical fund in 1984 and was faithful to them for all these years and never fail to make a payment until February 2022. In 2015 I removed my daughter from my medical aid as she was an adult, then she joined her medical aid. The same Bonitas. I have never been told that I am owing Bonitas R958.89 nor call or an email. I have never changed my email address or my cellphone number. Then in 2021 I received a call from the collectors saying I am owing Bonitas and they will suspend my membership. What is surprising is that they have been having my monthly premium every month even this month (February 2022) when my membership is suspended but my money is not suspended. My other question is that how can they get hold of me only in September 2021 and suspended my membership in February 2022. How can they claim an outstanding after 7 years. What happened to the write off of those charges. Today when I get to the dentist I was told that my membership is suspended. I'm on chronic and my dependent is also on chronic. I'm surprised that my monthly payments is not suspended, they are having my money.