Mtn & Huawei refuses to assist with factory fault

I bought a new Huawei P10 lite phone on contract through MTN. The phone were about 3 weeks old when I returned it to MTN Wonderpark due to the phone that's bended at the back where the battery is. Mtn sended it in to their repair center or what they want to call it. They came back and said the I damage or bend the phone maliciously. There no way that any person can bend a phone like that. The screen wil broke. I sent it back again but then they just let me know that they refuse to replace a factory fault. It's my own problem.