Patrick Motors Sold me a car advertised as CPO then stuck me with a repair bill two years later saying the car was not Certified. Auburn Massachusetts

This is pretty simple. I bought a car here that was advertised as CPO. I am not local so I drove fou hours to pickup the car. Two years later I went to my local dealer to have the car looked at and was stuck with a diagnostic bill because the car was never marked down as a certified VW. 

I called and spoke to someone at this dealership who kept me waiting for a week to try and get a resolution. My request was simple. Pickup my $130 diagnostic bill and we can call it even since my car's CPO warranty would have expired in the next few weeks anyway because I drive a lot. 

I was told this would not happen. I was polite and sent a link showing the original car advertised as CPO. I was even told that even though all cars are advertisied as Certified that does not mean they are. What the hell does that mean? 

I will never do business with this dealership again and plan to have a lawyer send a letter not only asking for a reimbursement of the bill, but also a reimbursement for my time and money. 

This is really a shame because I had a very modest and resonable request. Running a diagnostic on a car costs the dealer nothing, and could have easily been absored if they'd just called the other local dealer I took the car too and told them there was a misunderstanding.