Extremely disappointed, need urgent resolution

I have been paying premiums for plus minus 4 years now and receiving an sms after every premium that Hollard/21st century has received my payment. But to my surprise today when I called to get clarity on the premium increase I'm told I owe almost R2000 on my 2 policies because I defaulted in 2022, never was I informed of this and we are in 2024 and I get notified that my premiums have been received every month. I'm so appalled at the non communication and unprofessional service. After being sent from pillar to post by the call centers of Hollard and 21st century I have not received help.