Unfairness

I am divorced and currently according to the divorce am the sole owner of our joint property. I approach nedbank to have the property moved onto my name and the remaining amount outstanding to also be moved onto my name for payment. I get told to complete a section 45 form which I did. Today I get the quote back and guess what the loan amount has now shifted to the original amount that my ex and I had previously bought the house at. I ask u nedbank how can this be ? I have been paying for this house for 4 years now? Are u telling me that because I need to now remove my ex name my total outstanding amount increases to the original amount? Please explain this to me ? All I wanted was to continue paying the outstanding balance on my house and have the title moved to my name as per the court doc. But u can't give me the same rate? Yet I'm an approved bond applicant, no problems paying accounts ... No outstanding issues? Is this how u treat clients? Please can someone help me ? If anyone has had a similar experience. Please let me know ?