Mtn is taking me for a fool, they better bring back my Huawei P40 smart

I made a claim for my Huawei P40 smart, which was damaged by water, unfortunately they fail to fix it, and instead of me choosing a phone of my choice on the price range of my Huawei P40 smart, they choose to give me Huawei Nova 8i which came with a default, and I didn't notice the default for the first 3 weeks since the default was on the earphone port, the day I wanted to use headphones since i was touching water is where I realize that there was something and I heard to return it Back but now they have declined my claim.