Complaint Review: Hyundai

I leased a Hyundai Elantra a little more than a month ago. Hyundai advertises 29 miles/gallon in the city and 40 miles/gallon on highways and that was the only reason I bought the Elantra in the first place. With the gas prices shooting, I wanted a car that was great on mileage. 

But it turns out the whole mileage advertising is completely false...false advertising at its best. In the beginning I got only 21.3 miles/gallon in the city. I called the sales guy and he said that is very normal and people should start seeing improvements after 500 - 1000 miles of driving. It takes a while for the engine to break in. I waited patiently until the car hits 1000 miles and even after that I am lucky if I get 20 miles per gallon in the city. On some days it goes down to 19 miles/gallon. On the highway the best I got was 31.7 miles/gallon. 

Is this a joke? How can manufacturers get away with such bold lies? Are they allowed to advertise anything to allure people into buying their cars? I used to have a Toyota Corolla and I would spend around $100 on gas, my tank would have to be refilled every 12 days. With the Elantra I am refilling my tank every week and I end up spending $140 on gas. There was absolutely no reason for me to buy an Elantra if it hadn't been for the advertised mileage. 

It has been a month and I still don't have a registration sticker. The dealership said it was paid for when I took delivery of the car. I called PennDot and they have no paperwork from the dealership yet after more than a month. They don't even return my calls, what on earth is going on?

Either the dealership should take off a chunk of the price I paid for false advertising or reduce my monthly payments because I am spending more money on gas instead of saving some.