MTN and Samsung cellphone bad service

2019 I renewed my cell contract with MTN. I got a Samsung A30. I had the phone for five months and it started having problems with people can't hear me and dropping calls. January i took the phone to MTN so Samsung can have it repaird. Today is 29 October 2020 and i received my phone back after i have send it back to Samsung four times and every time they keep on saying the phone is fine, but the phone keeps on droping calls can people can't hear me. I bought a new sim and it still doesn't work. If i put my sim in a Huawei phone it works 100%. So Samsung refuses to replace the phone with a new one. The phone is on contract. Since January up to now i have been paying for a phone contract that i don't even have. Between Samsung and MTN they refuse to help me. Everytime i had to phone Samsung to find out where is the phone and how long will it take to have it repaired or replace it. The people at Samsung always told me they will get back to me but they never did. Samsung manager at KeyWest Krugersdorp doesn't seem to give a **** about my problem and doesn't seem to know much about cellphones herself but she's a manager. I have been supporting Samsung all my live and only believed in their phones, but i think after this bad experience fighting for a year i will rather support Huawei in the future. So now i got the phone back today but it still doesn't work and Samsung and MTN doesn't want to help. We have a contract with MTN for many years but that is also stoping this week. Never support Samsung or MTN.