Mtn p50 ****

I bought a brand new premium haiwai p50 pocket on contract 2 months ago. MTN sold me the phone even though they knew the phones had screen defects from the manufacturer. Now they don't want to take it back and give me a Samsung s22 ultra which is the same price. They want to repair the phone which will obviously give me the same issue later.im thinking of not paying anymore as I can't continue paying R1600 a month for a phone that I'm not using. The consumer protection act clearly states that I can take back the phone b4 6 months and ask 4 a different product.