2013 Car sold as 2014 Model

I bought a 2014 cheverolet Aveo 1.6 L in january 2015 for <br> <br> The vehicle was advertise as 2014 model (my signed contract says 2014) with full service history and balance of factory warranty<br> <br> up to now they couldnt give me the proof of all the servises wich in my opinion is a warranty void<br> <br> On the fourth of may we were contacted to let us know the car is a 2013 model and not a 2014 as the contract stipulated.<br> Later on that day they told me we can always cancell the contract, now they say i am responsible for the outstanding interest at the bank if we cancel the deal.