Hisense h60 5g - Poor Quality phone

Good Day, I resently upgraded my MTN contract after 4 years and 2 months due to my old Huawei p smart 2018 not receiving any new updates from Google. Here I am in my local MTN store with catalog in hand going through the latest deals. I'm not a Samsung fan but I was willing to look into it due to the lack of options. I'm not a vivo or an appo fan(no offense). I miss my Nokia and Sony phones. I went through the phones and contracts with the service agent in store and I was approached by the Hisense in store promoter. She advised on the new hisense h60 5g and showed me the promotional video on her hisense. I did explain to her that I was not a fan and she assured me that this phone is excellent for gaming and multi tasking. She also told me that the phone had duel apps and had Google updates. After 45min of to and fro I decided to take the Hisense H60 5g.i even purchased the gel screen protector and queried about a cover for the phone. The phone has a nice fit but is slightly larger than the phone I was replacing. The device worked well for the 1st 4 or 5 days then I started to notice the screen start to jump and the led looked like it was damaged. I took the phone back and I even took a video of the phone acting up. I was told that they would contact the supervisor. A few days later I was called to say that the device will be replaced. I waited for a week with no feedback and when I went back to the in store promoter she told me that there was no no stock of the device in the warehouse. I waited another week then I called back. I was told that stock will arrive at the warehouse at the end of the month (June). I asked for her Supervisors number to find out what was the delay but he never took my call nor did he return my call. Today is the 28th of June and my new contract will be debited from my account but I don't have my replacement device and this is the 3rd week of waiting. I'm worried about the remainder of the contract (23 months) what other issues I will have with this phone.