Chaos in the books

Truworths have been phoning me the whole week about her account .I have enquired from my wife how much she owes them and said R500.00.She gets paid on the 15 th of every month. She paid the account on the 14 th of October 2022 ,but i still get phoned on the 15 th .Seems like there is chaos in their books and they do not know what they are doing.