Nedbank home loan insurance ****

I recently noticed that my Nedbank home loan debit order increased by about R400. After contacting Nedbank I was told that building insurance was added to my account, even though I have my own insurance. No one from Nedbank contacted me about this additional amount, and I can't believe that they can just add amounts with no communication. After many phone calls and emails I cancelled the Nedbank insurance just to notice that the additional amount was again deducted this month. This is absolutely ridiculous, I have also been told that this amounts will not be credited to my bank account.