Cancel this upgrade! I don’t want it!

I am extremely fed up with mtn and rewards co! My package was upgraded by rewards co but I didn’t want this upgrade. I requested for the upgrade to be cancelled but over a month later I am still waiting for feedback! The lady from rewards co keeps telling me she has escalated the matter but doesn’t bother to get back to me. If I don’t call her she doesn’t bother herself! Can this matter please be rectified urgently. I am sick and tired of having to call through and being told the matter has been escalated. I demand a resolution to this matter!!