Debit order amendments with out consent or knowledge

every single month for the past 4 months MFC has been changing my debit order dates with out my knowledge so that they could charge me the full payment for my vehicles, every time the repo-rate dropped they amended and brought my debit order date forward with out my consent or knowledge this is absolute ******* they are such *******, also to date i have 2 vehicles with them and i dont get any statements, i will be moving by business to Wesbank.