I hate booking.com with passion

What **** , booking.com is *****ing from people. I made a flight booking for my mother from Zimbabwe to Johannesburg. I made a mistake instead of writing 7/4/24 l select 7/5/24 Only to realise soon after payment. I contacted them l was told to pay extra R2000 for changing the date. When I told them l didn't have that money they me to pay r300 because they were already changed the date