Frame And Members problems of the 2006 Ford Taurus

I have a 2006 Ford Taurus I bought a little over 2 years ago. It's seems like every other month or every 2 to 3 months I have to have a 4 wheel alignment. I have had the 4th set of tires I've had to have put on my car. The 1st 3 sets the dealer had to pay to have brand new ones put on. I had to spend over $800 to have 4 brand new tires and 2 brand new struts put on my car. Now 2 of the tires have begun cupping on the inside. I had to get 2 brand new tires put on just 2 weeks ago and the alignment had to be done again. I had to pay for the new tires. But all this is a little over 2 years to all these ties. No car should ever have to have 4 sets of tires put on there car. I believe my cars frame has been damaged or bent. It belonged to a rental car agency before I bought it form prime Toyota in saco maine. It was certified also. I got the car with a little over 27,00 miles on it. It now has a little over 82,00 on it. But still regardless of the miles or years there is no way that 4 sets of tires should;ve had to be put on my car. Just about everytime I get the alignment checked it cost me $ 40 and then more if adjustments are to be made. I don't have this kind of money. The car fax shows nothing.