Standard Bank home loan

I've had a home loan by Standard Bank which I got May 1996. 2016 I've paid it up. Last year 2023 they phoned saying I must cancel my bond. I've send them a email stating I want to cancel my bond but never got a reply once back. March 2023 they phoned saying I'm behind with my home loan and I told her I paid for my bond already. I went to Standard Bank and they put me through to the home loan department I spoke with 6 different people that day and they kept ending the call everytime I tell them my bond is paid up. Now they keep calling but once I pick up they end the call on their side. Some of them say I'm behind with my bond and some say I'm behind with my insurance and they are demanding the money which I apparently is in arrears with.