Afrihost unfair greed tactics.

I cancel my subscription on the first working day of August 2026 as i was moving out my flat. Because the first working day was 3 August, they make me pay until end of September. Wasting R717 as i was paying for no service. I believe adding such devious cancelation detail in a terms and conditions is only there to unfairly get an additional month subscription. Surely with all the working days of a month they can stop the debit order?