Am I a victim of racial bias at MFC, do I need to get help regarding my contract with MFC in order to avoid being ****med?

I bought a car with MFC December 2019. Prior to signing the contract I had discussion with the manager at the dealership. I walked out knowing and understand very well what I would be paying however the first debit went off yesterday and it is more than what I signed. A week ago I got my statement and on there I saw what the installment would be. The debit that went off is not even that. I do not understand why this is so. I sent an email to MFC yesterday hoping I would get response today however noone has gotten back to me with an explanation. I sent a second email and still nothing. My concern now is that Nedbank may be doing what banks have been said to doing to their African clients where they increase interest rate without your knowledge. Could I be a victim of racial bias at MFC?