Overbilled

I actually believe i am unlucky with the service from City Property. My apartment is lovely, building caretaker and security guards have awesome service. My issue is with the office, I'm renting at Splendid Place and I'm having an issue with Tax Invoice all the time, it's actually exhausting. First time moving in by July they overcharged me on parking and Resego Moalosi fixed it, i was so happy that atleast someone can take responsibility off their offices' incompetence. But here i am again now i have been overcharged with parking for Sept invoice, i wrote to Rachel Nhlapo on the 26/08/21 to correct it so i can make the payment for my rent. She calls yesterday and she's actually made it my problem. She explains they havent been charging me parking for Sept-Nov 2020 hence they are adding it now and I'm liable for a payment. Tell me, howdo i become liable for such incompetence? I always pay my rent on time, correctly so as per invoices sent to me monthly. So obviously this can't be my problem, whoever made a mistake has to fix it so i can continue living stress-free. I don't owe anyone as i always pay my rent on time as per the invoices they sent me. I am so not happy because all i do is pay correctly monthly. Right now it's month end, they haven't fixed it and I'm living scared every minute that what if they switch off my lights and I'm in a different province. Please City Property let's do better and fix this, all i am is loyal to yall monthly