Rain debited account after internet was cancelled and suspended.

Good day, I am very disappointed that Rain debited my account after I canceled my internet with them. They canceled my service but on the 1st of September, they still debited my account. I emailed them numerous times and also went on their app and received a ticket number but no one ever contacted me or responded to my email. Rain wants to send a courier company to fetch the router but I won't give back the router until I receive my refund.