I found an o-ring in my Target Brand Milk Jug.?

I drank the whole jug, all one gallon's worth, over a few days. In my last pour I didn't notice the o-ring fall in the cup, but I heard something strange. I looked all over the milk and in the jug. Nothing. Then I drank the gl, and in my last gulp I almost swallowed a black rubber o-ring 2cm in diameter. I didn't choke, but was terribly grossed out. I called Target and they have come to pick up the gallon jug and the o-ring. They are mailing me two vouchers for $3.67 (the price of the milk). I think this was terrible. Not only that their quality control didn't find this, but that I could have swallowed it and gotten it in my system. Should Target do something else about this? Should I pursue any other action?