Account changed without my consent.

I was contacted by FNB (Sibongile Mgobozi) to "upgrade" my account, I was told everything will be mailed to me, but before anything was mailed to me the person changed my account without my permission. After receiving the documents and going through them I decided not to change my account, now I can't get hold of her, she doesn't return my calls and the call center have the same story every time "we will sent her a mail and she will contact you, as she is the only person that can sort this out" My account was changed without my consent and I need this sorted out.