Science told them they could get pregnant while using the contraceptive. Their ignorance of science failed them, not science itself, if they thought they couldn't get pregnant.
Can I blame science if I shoot myself playing Russian Roulette, since science says putting only one round in the revolver (instead of six) reduces my chances of getting shot? If I get shot, is it because science failed me?
I don't know... I suppose if resurrection were an option you'd have said something relevant to the discussion. The fact is that contraceptives, while sold with warnings, are often expected and intended to be absolute. When that fails, there are other means that people can avail themselves of, either chemical or procedural.
The only case I see you making here is that you don't like abortion. We both know that the crux of marketing lies in exploiting human weakness, such as those one WhoWee points out. In the classic, "You have three doors, behind one of which is a prize! You open door #1, and it's empty, but you now have a chance to switch your choice, or stay... what do you do?" turns out that plenty of people stay, or switch for all fo the wrong reasons. You switch, and your odds increase... period, but are you saying that our population control should be predicated on a working knowledge of math and statistics?
Lets get people literate first... which by the way, will be easier if they stay in school instead of carrying a child to term.