Walk-Behind Mowers

I purchased a Poulan Pro walk behind mower on 5/17/2016. Used it three times and then quit working. The mower stopping running and all the oil leaked out. On closer inspection, I could see there was a crack in the engine mount right below the oil chamber. I purchased it from Menard's and they sent me to a service provider who said I must have ran over something and that's it's not repairable under warranty. Basically I am out $200. I don't recall running over anything. I can't understand how this mower can be put together so cheaply that it breaks on the third use from normal use. Where can I go from here. I can't afford to purchase another mower!