On Air is in a mission to ruin my reputation

They promised me a phone call on my previous complaint, but nothing. I only received a very rude WhatsApp message. It is not end there. I have received this SMS today..."FINAL NOTICE, Today is the last day for a payment of R597.00 to be made to OnAir. Failure to pay will result possible action on your account. Pay TODAY by clicking on the link https://swiffy.co.za/u/qQCkHg5q or pay via Banking Details: ABSA Acc Number ***; Branch 632005. Call ***. Ref: OA-***2-1." I give up...I only know IsiZulu and English. There is no other language I can use to pass a message that I have no outstanding payment. I even sent PoP by WhatsApp and emails. I wish I can just return their decoder and move on with my life. I curse the day I interacted with them