Incorrect online monthly repayment calculator

We are in the process of buying a new vehicle for my husband. Finance already approved through Wesbank. <br> Using the exact same figures (principal debt, interest rate, term and balloon payment) the monthly repayment is different between the wesbank approval letter and the wesbank website.<br> <br> This is absolutely unacceptable as the same algorithm should be used to calculate the repayments (whether backend or customer facing). It does not make any logical sense that Wesbank would have separate algorithms as this would mean two requirements that should be maintained in the came of any changes.<br> <br> How is it possible if all things being equal that the website gives R3605.05 (including initiation fee + monthly service fee) and the approval gives R3738.14 (including initiation fee but excluding the monthly service fee)?<br> <br> The website is only an estimate IF the customer does not know for a FACT what their finance terms would be (ITC profile etc.) <br> <br> In this instance we have a confirmed approved interest rate etc.<br> <br> It is only logical that the amounts given should then be a match.<br> <br> Urgently contact me so that the repayment can be adjusted to match your website.