Paid R1850 but only R900 available on account?

Can someone from accounts department please confirm why was R1850 paid on my account but there is only R900 available. Please ensure all payments were indeed allocated. 26.06.2023 – R400 11.07.2023 – R200 13.07.2023 – R200 21.07.2023 – R300 26.07.2023 - R350 04.08.2023 – R400

TOTAL: R 1850