Rain issues on billing

So I cancelled my Rain subscription around end of Aug2024, I proceeded to return the device on the 7th Sept 2024. I was informed that I have a post paid account and that I would still need to pay a final payment at the end of Sept. After checking all the details I could not see how that was possible. But to avoid any issues at the end of September I proceeded to pay the last final payment. I then made contact with rain. Firstly the agent confirmed receiving the payment, and also confirming a R0.00 balance left. I then requested for them to remove my details. The app or web offers you no option to delete your account. I even said to the lady that it was to avoid my details lying around for them to attempt any deductions. And guess what, I received a notification of an attempt to deduct money from rain. Luckily the account was at the stage on R0,00. I proceeded to call rain. I am now told that there is a Overdue account of a R185.00. So how is this now possible? The guy says he can see the escalation of the request to remove my account details due to a R0.00 outstanding account and also confirmed that perhaps billing never updated? I mean on the 10 October I received a sms stating that my service have been interupted? This after it was cancelled and paid up?