Double Debit: Credit Life insurance

I have a personal loan with African Bank, some months ago I changed the African Bank Credit insurance to an external insurance, the process was a nightmare because they kept giving me run around, eventually they accepted and my insurance was switched,

This month they decided to reinstate their own insurance without any notice, now I am paying double insurance for the same loan, I have been trying to get hold of them on the phone , on email no one is responding

I just need this error fixed and my money back.