Unauthorized payments

I stopped using my rain simcard because we have Fibre at home, so I was under the impression that it was inactive so I didn't worry to cancel it, so last month my account was debited and I enquired about it and they had told me that I never canceled it so they had to debit me due to an active account and I was fine with it and told them to please cancel my account as I will not be using it anymore, so they told me that my account is scheduled to cancel at the end of July and my last installment will go off on the first of August. However today money was taken out of my account without my consent and they are looking for every excuse not to refund me. Last month they told me that rain is a post payment and seeing that my account was canceled last month and not used during August. I don't see why money was removed from my account today.