Unfairly wronged

Hi I've joined herotel on 22 August 2025 I've paid R840 for the 2 weeks in August and September and made another payment on 9 September 2025 of R620 now they invoice me R595 for October I mean I've already made 3 payments in 1 month and a half im suppost to pay from the first of next month this company needs to be dealt with they keep on doing this .