How do i get rid of ants in my refrigerator?

I bought an apartment size refrigerator. It was in a garage when I looked at it. It was very clean but had some ants crawling on it. I thought nothing of it. I got it into my 3rd floor apartment and soon ants are not only on it, but in it - in the freezer and the refrigerator. I cleaned the entire unit. I vacuumed the entire thing; every open space, the inside of the compressor as best I could and everything. I closed the door and came back an hour later. Ants everywhere!! I sprayed the entire inside with windex including the air vents. There are still ants living inside the refrigerator. Is there any way to really get rid of the ants or do I need to return the refrigerator? PLEASE HELP