Rain mobile - Outstanding amount

First and foremost there is no contract between me and Rain, I was using their R699 month to month service, until I moved to another neighborhood. Rain have no network coverage were I'm currently residing hence I had to stop/ cancel using their service and they did come fetch their rooter and I did receive an sms from them that they did collect the rooter at my house. Months later I have been receiving messages that I have an outstanding balance of R1496.00 which I did pay but I'm still getting messages that I owe an outstanding of R1256.30.

Please help me.