MTN refusing to deliver router that has been paid for and won’t give refund

I ordered a month to month router with them and paid the full amount for connection and the month of December. They say the order was cancelled on their side due to non payment. And they want proof of payment, I have sent them every reference number, my card number, bank statement and still I’m being sent to pillar to post by these “champions” because no one wants to tell me where the device is, I even asked for a refund and they declined that as well, so I basically gave a huge corporation money for fun.