Walk Behind Lawn Mowers

During the first use of the lawn mower, I noticed the blade break arm was bent. I need to get it replaced. The plastic piece with the spring was in the bottom of the box and because of the bend i could not get it back on. I need the whole arm and plastic piece with spring replaced. I purchased the mower on 3/25/17 at Lowes. Since I have already ran the lawn mower I prefer not to take it back and just get the part if possible. The model is HU725AWD/BBC.