Suspension

2010 Chevy Impala LTZ I recently got (making payments) less then three months ago is eating the inside of all my tires (found this out when one of my back tire had a blow out, and the digital odometer always told me my front tire was low, which I always check the air put the PSI I got for the air pressure never match the PSI on odometer, I been complaining about the shortly after getting car). I did some research learned it needs an all wheel drive alignment and four new tires (possibly more depending). I understand I bought the car as is as I explained to the dealership, and my warranty only covers the power train. But I just don't understand how I drove it off the lot and am in this situation to begin with. I have been asking my dealership, when they did the inspection before putting it out to sale, did they not catch it being unaligned did they not even check or is this something that simply happen over night? T I am lose here and honestly I can not afford to replace these items and I am nervous to even drive my car with my child. Dealerships says it is not their responsibility to fix it or atleast help. An they still will not answer this question was the alignment even looked at to begin with. Im not trying to place blame it could have happen over night, im completely lost, im stuck with my car needing an all wheel alignment and four new tires. Can this be right?