Rain ****med double payment due to cancellation

I started using Rain in 2020 until this year March when I informed them that I am terminating with them since I have been retrenched and won't be able to proceed with them.They advised me to process my termination on the app which I did .come month end they still deducted my money and deducted double which is R1070 I wrote them several messages requesting them to return my money ,but they are not doing so. I still do not understand the reason for double deduction maybe they are penalising me for leaving