CPO with multiple accidents

I purchased 2011 X3 from Crevier BMW CA back in 2015 as CPO. They told me they never mark their car as CPO if it was involved in any accident. CarFax showed no accident and the car looked like new.

I took it to CarMax several days ago to see how much it is worth and they pulled AutoCheck report and told me that the car was involved in a multiple accident and the air-bag was deployed. CarMax appraised my car at a very low price because of the accident records.

I feel so cheated that Crevier lied about the condition of the car and I paid extra for being a CPO. I called the dealer and they provided the CarFax report again and they also say they'd never sell a car with accident history.
I showed them the AutoCheck report I got from CarMax and immediately they offered to take the car back. Obviously, much lower than how much I could've got if it wasn't in any accident.

I was so upset (still am) and just wanted to get rid of the car so I took it back to them. Now few days later, I see the car listed as "no accident" with same CarFax report from a private used car dealer.

Do not buy cars from Crevier and don't trust CarFax.
And do not buy VIN: 5UXWX5C57BL715299

Carfax and carmax's auto check both lie. I bought a car from carmax and their auto check said no accidents and i did a carfax on it and carfax showed an accident. those auto check websites shouldnt be fully trusted.

Can't you sue? I would assume this would fall under false advertising.