Incorrectly adding fees

I took out a term loan from Capitec for R90759.79, the agreed instalment, which included fees and interest, was R2777.89. The amount was deducted on the 27th, and the outstanding balance was correctly accredited as R88197.90. A few hours later when I was doing another transaction on the banking app I noticed that the amount had again increased to R90548.13. I queried this with Capitec and was told those are fees and interest added onto the loan. But what fees and interest? Because those were included on the initial instalment. Secondly, the interest they have now added is R1952.25 which was added after the deduction, but the interest on the loan is 24.50% which is R22,289.07 which should be R318.42 a month. And why would these fees be added on after the fact? After the deduction because fees and interest is factored in the instalment.