bad services

I did an upgrade last year December on the 16 of December 2023, I took honor phone which was a combo for R528 and now i received my bill for Jan and Feb which I have been chargered separetly for the device, I went to MTN store in Fourways and they logged a call last week and they picked up that im charged combo and device separetly, I have been calling since last week MTN call centre for this issue to be resolved but nothing yet has been resolved and still my statement is incorrect and I am suffering as a client and no one is helping i need my refund i regret why i did an upgrade, pathetic service no one knows anything, agents are rude

Can i have my bill corrected and refunded