Refrigerator door closer, lower cam and cam-door

I purchased a cam-door - part number AP3046922 and a door closer-lower cam - AP2979611. i was able to install the lower cam but when i got to the door-cam, the once with the post on it, it did not fit in the hole of the door. Does anyone know why? When i removed the worn out parts, it appeared that both sides looked like the lower cam (without the post).

please help.

Thanks
Alex