Dstv/cubix unsolicited calls

How can I get cubic/qubix? To stop phoning me on behalf of Dstv to insure or upgrade my decoder. I’ve opted out of all Dstv marketing on their app yet I still get at least 5 calls a week from these people. I keep blocking the number and a new one comes up. I don’t need another decoder and if mine breaks I’ll just switch to stream . Leave me alone otherwise I am going to cancel Dstv entirely. I only keep it for the sport and don’t even watch any other content on there.